diff --git a/frontend/src/layouts/ApiHubLayout.tsx b/frontend/src/layouts/ApiHubLayout.tsx
index 331c72a..344c74e 100644
--- a/frontend/src/layouts/ApiHubLayout.tsx
+++ b/frontend/src/layouts/ApiHubLayout.tsx
@@ -122,20 +122,20 @@ const ApiHubLayoutInner = () => {
   return (
     <div className="flex min-h-screen">
       {/* Sidebar */}
-      <aside className="fixed left-0 top-0 h-screen w-[272px] bg-gray-900 flex flex-col">
+      <aside className="fixed left-0 top-0 h-screen w-[272px] bg-[var(--color-bg-surface)] flex flex-col border-r border-[var(--color-border)]">
         {/* 로고 영역 */}
-        <div className="flex-shrink-0 border-b border-gray-700/70">
+        <div className="flex-shrink-0 border-b border-[var(--color-border)]">
           <button
             onClick={() => navigate('/api-hub')}
-            className="flex items-center gap-3 px-5 h-14 w-full hover:bg-gray-800/60 transition-colors"
+            className="flex items-center gap-3 px-5 h-14 w-full hover:bg-[var(--color-primary-subtle)] transition-colors"
           >
-            {/* Indigo 그라디언트 아이콘 배경 */}
-            <div className="flex h-8 w-8 flex-shrink-0 items-center justify-center rounded-lg bg-gradient-to-br from-indigo-500 to-violet-600 shadow-lg">
+            {/* 브랜드 컬러 아이콘 배경 */}
+            <div className="flex h-8 w-8 flex-shrink-0 items-center justify-center rounded-lg bg-[var(--color-primary-600)] shadow-lg">
               <svg className="h-4.5 w-4.5 text-white" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth={2} strokeLinecap="round" strokeLinejoin="round">
                 <path d="M12 6.253v13m0-13C10.832 5.477 9.246 5 7.5 5S4.168 5.477 3 6.253v13C4.168 18.477 5.754 18 7.5 18s3.332.477 4.5 1.253m0-13C13.168 5.477 14.754 5 16.5 5c1.747 0 3.332.477 4.5 1.253v13C19.832 18.477 18.247 18 16.5 18c-1.746 0-3.332.477-4.5 1.253" />
               </svg>
             </div>
-            <span className="text-sm font-bold tracking-widest text-white uppercase">KCG API HUB</span>
+            <span className="text-sm font-bold tracking-widest text-[var(--color-text-primary)] uppercase">KCG API HUB</span>
           </button>
         </div>
 
@@ -143,7 +143,7 @@ const ApiHubLayoutInner = () => {
         <div className="flex-shrink-0 px-4 pt-4 pb-2">
           <div className="relative">
             <svg
-              className="absolute left-2.5 top-1/2 -translate-y-1/2 h-3.5 w-3.5 text-gray-500 pointer-events-none"
+              className="absolute left-2.5 top-1/2 -translate-y-1/2 h-3.5 w-3.5 text-[var(--color-text-tertiary)] pointer-events-none"
               fill="none"
               viewBox="0 0 24 24"
               stroke="currentColor"
@@ -155,12 +155,12 @@ const ApiHubLayoutInner = () => {
               value={searchQuery}
               onChange={(e) => setSearchQuery(e.target.value)}
               placeholder="API 검색..."
-              className="w-full bg-gray-800 border border-gray-700 text-gray-200 placeholder-gray-600 rounded-lg pl-8 pr-7 py-2 text-xs focus:ring-1 focus:ring-indigo-500 focus:border-indigo-500 focus:outline-none transition-colors"
+              className="w-full bg-[var(--color-bg-base)] border border-[var(--color-border)] text-[var(--color-text-primary)] placeholder-[var(--color-text-tertiary)] rounded-lg pl-8 pr-7 py-2 text-xs focus:ring-1 focus:ring-[var(--color-primary)] focus:border-[var(--color-primary)] focus:outline-none transition-colors"
             />
             {searchQuery && (
               <button
                 onClick={() => setSearchQuery('')}
-                className="absolute right-2 top-1/2 -translate-y-1/2 text-gray-600 hover:text-gray-400 transition-colors"
+                className="absolute right-2 top-1/2 -translate-y-1/2 text-[var(--color-text-tertiary)] hover:text-[var(--color-text-secondary)] transition-colors"
               >
                 <svg className="h-3.5 w-3.5" fill="none" viewBox="0 0 24 24" stroke="currentColor">
                   <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M6 18L18 6M6 6l12 12" />
@@ -170,7 +170,7 @@ const ApiHubLayoutInner = () => {
           </div>
           {/* API 수 요약 */}
           {!loading && (
-            <p className="mt-2 text-[11px] text-gray-600">
+            <p className="mt-2 text-[11px] text-[var(--color-text-tertiary)]">
               {filteredDomainGroups.length}개 도메인 · {filteredDomainGroups.reduce((s, dg) => s + dg.apis.length, 0)}개 API
             </p>
           )}
@@ -180,13 +180,13 @@ const ApiHubLayoutInner = () => {
         <nav className="flex-1 overflow-y-auto px-2 py-1 space-y-0.5">
           {loading ? (
             <div className="flex items-center justify-center py-10">
-              <svg className="h-5 w-5 animate-spin text-gray-600" fill="none" viewBox="0 0 24 24">
+              <svg className="h-5 w-5 animate-spin text-[var(--color-text-tertiary)]" fill="none" viewBox="0 0 24 24">
                 <circle className="opacity-25" cx="12" cy="12" r="10" stroke="currentColor" strokeWidth="4" />
                 <path className="opacity-75" fill="currentColor" d="M4 12a8 8 0 018-8V0C5.373 0 0 5.373 0 12h4z" />
               </svg>
             </div>
           ) : filteredDomainGroups.length === 0 ? (
-            <p className="text-xs text-gray-600 text-center py-6">검색 결과가 없습니다</p>
+            <p className="text-xs text-[var(--color-text-tertiary)] text-center py-6">검색 결과가 없습니다</p>
           ) : (
             filteredDomainGroups.map((dg, domainIndex) => {
               const domainOpen = isSearching || (openDomains[dg.domain] ?? true);
@@ -195,7 +195,7 @@ const ApiHubLayoutInner = () => {
               return (
                 <div key={dg.domain} className="mb-0.5">
                   {/* 도메인 헤더 */}
-                  <div className="flex w-full items-center rounded-lg hover:bg-gray-800/50 transition-colors group">
+                  <div className="flex w-full items-center rounded-lg hover:bg-[var(--color-primary-subtle)] transition-colors group">
                     {/* 도메인명 클릭 → 도메인 상세 페이지 이동 */}
                     <button
                       onClick={() => navigate(`/api-hub/domains/${encodeURIComponent(dg.domain)}`)}
@@ -217,7 +217,7 @@ const ApiHubLayoutInner = () => {
                           ))}
                         </svg>
                       </div>
-                      <span className="flex-1 truncate text-xs font-semibold text-gray-300 group-hover:text-white transition-colors tracking-wide">
+                      <span className="flex-1 truncate text-xs font-semibold text-[var(--color-text-secondary)] group-hover:text-[var(--color-primary-text)] transition-colors tracking-wide">
                         {dg.domain}
                       </span>
                       {/* API 카운트 뱃지 */}
@@ -228,7 +228,7 @@ const ApiHubLayoutInner = () => {
                     {/* 접힘/펼침 화살표 버튼 */}
                     <button
                       onClick={() => toggleDomain(dg.domain)}
-                      className="flex-shrink-0 rounded-md p-1.5 mr-1 text-gray-600 hover:text-gray-400 transition-colors"
+                      className="flex-shrink-0 rounded-md p-1.5 mr-1 text-[var(--color-text-tertiary)] hover:text-[var(--color-text-secondary)] transition-colors"
                       title={domainOpen ? '접기' : '펼치기'}
                     >
                       <svg
@@ -244,7 +244,7 @@ const ApiHubLayoutInner = () => {
 
                   {/* API 항목 목록 */}
                   {domainOpen && (
-                    <div className="ml-3 mt-0.5 space-y-0.5 border-l border-gray-800 pl-3">
+                    <div className="ml-3 mt-0.5 space-y-0.5 border-l border-[var(--color-border)] pl-3">
                       {dg.apis.map((api) => {
                         const apiPath = `/api-hub/services/${api.serviceId}/apis/${api.apiId}`;
                         const isActive = location.pathname === apiPath;
@@ -255,13 +255,13 @@ const ApiHubLayoutInner = () => {
                             to={apiPath}
                             className={`flex items-center gap-2 rounded-md px-2 py-1.5 text-xs truncate transition-colors ${
                               isActive
-                                ? 'bg-gray-800 text-white font-medium'
-                                : 'text-gray-500 hover:bg-gray-800/60 hover:text-gray-200'
+                                ? 'bg-[var(--color-primary)] text-white font-medium dark:bg-[var(--color-primary-subtle)] dark:text-[var(--color-primary-text)]'
+                                : 'text-[var(--color-text-secondary)] hover:bg-[var(--color-primary-subtle)] hover:text-[var(--color-primary-text)]'
                             }`}
                           >
                             {/* 활성 시 좌측 도트 인디케이터 */}
                             <span className={`flex-shrink-0 h-1.5 w-1.5 rounded-full transition-colors ${
-                              isActive ? `${color.dot}` : 'bg-gray-700'
+                              isActive ? `${color.dot}` : 'bg-[var(--color-border)]'
                             }`} />
                             <span className="truncate">{api.apiName}</span>
                           </NavLink>
@@ -277,8 +277,8 @@ const ApiHubLayoutInner = () => {
 
         {/* 하단 정보 */}
         {!loading && (
-          <div className="flex-shrink-0 border-t border-gray-700/70 px-4 py-3">
-            <div className="flex items-center justify-between text-[11px] text-gray-600">
+          <div className="flex-shrink-0 border-t border-[var(--color-border)] px-4 py-3">
+            <div className="flex items-center justify-between text-[11px] text-[var(--color-text-tertiary)]">
               <span>전체 {totalApiCount}개 API</span>
               <span>{domainGroups.length}개 도메인</span>
             </div>
@@ -289,13 +289,13 @@ const ApiHubLayoutInner = () => {
       {/* Main content */}
       <div className="flex-1 ml-[272px]">
         {/* 헤더 */}
-        <header className="h-14 bg-gray-900 border-b border-gray-700/70 flex items-center justify-between px-6">
+        <header className="h-14 bg-[var(--color-bg-surface)] border-b border-[var(--color-border)] flex items-center justify-between px-6">
           <div />
           <div className="flex items-center gap-3">
             {/* 테마 토글 */}
             <button
               onClick={toggleTheme}
-              className="rounded-lg p-2 text-gray-500 hover:bg-gray-800 hover:text-gray-300 transition-colors"
+              className="rounded-lg p-2 text-[var(--color-text-secondary)] hover:bg-[var(--color-bg-base)] hover:text-[var(--color-text-primary)] transition-colors"
               title={theme === 'light' ? 'Dark mode' : 'Light mode'}
             >
               {theme === 'light' ? (
@@ -309,15 +309,15 @@ const ApiHubLayoutInner = () => {
               )}
             </button>
             {/* 역할 스위처 (알약 형태) */}
-            <div className="flex rounded-full overflow-hidden border border-gray-700 bg-gray-800 p-0.5">
+            <div className="flex rounded-full overflow-hidden border border-[var(--color-border)] bg-[var(--color-bg-base)] p-0.5">
               {ROLES.map((role) => (
                 <button
                   key={role}
                   onClick={() => setRole(role)}
                   className={`rounded-full px-3 py-1 text-xs font-medium transition-colors ${
                     user?.role === role
-                      ? 'bg-indigo-600 text-white shadow-sm'
-                      : 'text-gray-500 hover:text-gray-300'
+                      ? 'bg-[var(--color-primary)] text-white shadow-sm dark:bg-[var(--color-primary-600)]'
+                      : 'text-[var(--color-text-tertiary)] hover:text-[var(--color-text-secondary)]'
                   }`}
                 >
                   {role}
@@ -328,7 +328,7 @@ const ApiHubLayoutInner = () => {
         </header>
 
         {/* 콘텐츠 */}
-        <main className="p-6 bg-gray-100 dark:bg-gray-900 min-h-[calc(100vh-3.5rem)]">
+        <main className="p-6 bg-[var(--color-bg-base)] min-h-[calc(100vh-3.5rem)]">
           <Outlet />
           <BasketFloatingPanel />
         </main>
@@ -355,22 +355,22 @@ const BasketFloatingPanel = () => {
         !isBasketOpen ? (
           <button
             onClick={() => setBasketOpen(true)}
-            className="fixed right-6 bottom-6 z-40 flex items-center gap-2 rounded-xl bg-indigo-600 hover:bg-indigo-700 text-white px-4 py-3 shadow-lg transition-colors"
+            className="fixed right-6 bottom-6 z-40 flex items-center gap-2 rounded-xl bg-[var(--color-primary)] hover:bg-[var(--color-primary-hover)] dark:bg-[var(--color-primary-600)] dark:hover:bg-[var(--color-primary-500)] text-white px-4 py-3 shadow-lg transition-colors"
           >
             <svg className="h-5 w-5" fill="none" viewBox="0 0 24 24" stroke="currentColor">
               <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M3 3h2l.4 2M7 13h10l4-8H5.4M7 13L5.4 5M7 13l-2.293 2.293c-.63.63-.184 1.707.707 1.707H17m0 0a2 2 0 100 4 2 2 0 000-4zm-8 2a2 2 0 11-4 0 2 2 0 014 0z" />
             </svg>
             <span className="text-sm font-semibold">신청함</span>
-            <span className="flex h-5 w-5 items-center justify-center rounded-full bg-white text-indigo-700 text-xs font-bold">{items.length}</span>
+            <span className="flex h-5 w-5 items-center justify-center rounded-full bg-white text-[var(--color-primary-active)] text-xs font-bold">{items.length}</span>
           </button>
         ) : (
-          <div className="fixed right-6 bottom-6 z-40 w-80 rounded-xl bg-white dark:bg-gray-800 shadow-2xl border border-gray-200 dark:border-gray-700 flex flex-col max-h-96">
-            <div className="flex items-center justify-between px-4 py-3 border-b border-gray-200 dark:border-gray-700 flex-shrink-0">
-              <span className="text-sm font-bold text-gray-900 dark:text-gray-100">
+          <div className="fixed right-6 bottom-6 z-40 w-80 rounded-xl bg-[var(--color-bg-surface)] shadow-2xl border border-[var(--color-border)] flex flex-col max-h-96">
+            <div className="flex items-center justify-between px-4 py-3 border-b border-[var(--color-border)] flex-shrink-0">
+              <span className="text-sm font-bold text-[var(--color-text-primary)]">
                 API 신청함
-                <span className="ml-1.5 inline-flex items-center justify-center h-5 min-w-5 rounded-full bg-indigo-100 dark:bg-indigo-900/50 text-indigo-700 dark:text-indigo-300 text-xs font-bold px-1">{items.length}건</span>
+                <span className="ml-1.5 inline-flex items-center justify-center h-5 min-w-5 rounded-full bg-[var(--color-primary-subtle)] text-[var(--color-primary)] text-xs font-bold px-1">{items.length}건</span>
               </span>
-              <button onClick={() => setBasketOpen(false)} className="text-gray-400 hover:text-gray-600 dark:hover:text-gray-300 transition-colors">
+              <button onClick={() => setBasketOpen(false)} className="text-[var(--color-text-secondary)] hover:text-[var(--color-text-primary)] transition-colors">
                 <svg className="h-4 w-4" fill="none" viewBox="0 0 24 24" stroke="currentColor"><path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M6 18L18 6M6 6l12 12" /></svg>
               </button>
             </div>
@@ -385,12 +385,12 @@ const BasketFloatingPanel = () => {
                 });
                 return Array.from(grouped.entries()).map(([domain, apis]) => (
                   <div key={domain}>
-                    <div className="px-4 py-1.5 bg-gray-50 dark:bg-gray-700/50 border-b border-gray-100 dark:border-gray-700/50">
-                      <span className="text-xs font-semibold text-gray-500 dark:text-gray-400 uppercase tracking-wider">{domain}</span>
+                    <div className="px-4 py-1.5 bg-[var(--color-bg-base)] border-b border-[var(--color-border)]">
+                      <span className="text-xs font-semibold text-[var(--color-text-secondary)] uppercase tracking-wider">{domain}</span>
                     </div>
                     {apis.map((item) => (
-                      <div key={item.apiId} className="flex items-center gap-2 px-4 py-2 border-b border-gray-50 dark:border-gray-700/30">
-                        <span className="flex-1 text-sm text-gray-800 dark:text-gray-200 truncate">{item.apiName}</span>
+                      <div key={item.apiId} className="flex items-center gap-2 px-4 py-2 border-b border-[var(--color-border)]">
+                        <span className="flex-1 text-sm text-[var(--color-text-primary)] truncate">{item.apiName}</span>
                         <button onClick={() => removeItem(item.apiId)} className="flex-shrink-0 text-gray-400 hover:text-red-500 transition-colors">
                           <svg className="h-3.5 w-3.5" fill="none" viewBox="0 0 24 24" stroke="currentColor"><path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M6 18L18 6M6 6l12 12" /></svg>
                         </button>
@@ -400,9 +400,9 @@ const BasketFloatingPanel = () => {
                 ));
               })()}
             </div>
-            <div className="flex gap-2 px-4 py-3 border-t border-gray-200 dark:border-gray-700 flex-shrink-0">
-              <button onClick={clearItems} className="flex-1 rounded-lg border border-gray-300 dark:border-gray-600 bg-white dark:bg-gray-700 text-gray-700 dark:text-gray-300 hover:bg-gray-50 dark:hover:bg-gray-600 text-xs font-medium py-2 transition-colors">전체 삭제</button>
-              <button onClick={handleOpenModal} className="flex-1 rounded-lg bg-indigo-600 hover:bg-indigo-700 text-white text-xs font-medium py-2 transition-colors">일괄 신청</button>
+            <div className="flex gap-2 px-4 py-3 border-t border-[var(--color-border)] flex-shrink-0">
+              <button onClick={clearItems} className="flex-1 rounded-lg border border-[var(--color-border-strong)] bg-[var(--color-bg-surface)] text-[var(--color-text-primary)] hover:bg-[var(--color-bg-base)] text-xs font-medium py-2 transition-colors">전체 삭제</button>
+              <button onClick={handleOpenModal} className="flex-1 rounded-lg bg-[var(--color-primary)] hover:bg-[var(--color-primary-hover)] dark:bg-[var(--color-primary-600)] dark:hover:bg-[var(--color-primary-500)] text-white text-xs font-medium py-2 transition-colors">일괄 신청</button>
             </div>
           </div>
         )
diff --git a/frontend/src/layouts/MainLayout.tsx b/frontend/src/layouts/MainLayout.tsx
index e91db67..ec7c80d 100644
--- a/frontend/src/layouts/MainLayout.tsx
+++ b/frontend/src/layouts/MainLayout.tsx
@@ -198,40 +198,40 @@ const MainLayout = () => {
   return (
     <div className="flex min-h-screen">
       {/* Sidebar */}
-      <aside className="fixed left-0 top-0 h-screen w-60 bg-gray-900 text-white flex flex-col z-40">
+      <aside className="fixed left-0 top-0 h-screen w-60 bg-[var(--color-bg-surface)] text-[var(--color-text-secondary)] flex flex-col z-40 border-r border-[var(--color-border)]">
 
         {/* 로고 영역 */}
-        <div className="flex items-center gap-3 px-4 h-14 border-b border-gray-700/60 flex-shrink-0">
-          <div className="flex items-center justify-center w-8 h-8 rounded-lg bg-gradient-to-br from-indigo-500 to-indigo-700 flex-shrink-0">
+        <div className="flex items-center gap-3 px-4 h-14 border-b border-[var(--color-border)] flex-shrink-0">
+          <div className="flex items-center justify-center w-8 h-8 rounded-lg bg-[var(--color-primary-600)] flex-shrink-0">
             <svg fill="none" viewBox="0 0 24 24" stroke="currentColor" strokeWidth={2} strokeLinecap="round" strokeLinejoin="round" width={16} height={16} className="text-white">
               <path d="M10 13a5 5 0 007.54.54l3-3a5 5 0 00-7.07-7.07l-1.72 1.71" />
               <path d="M14 11a5 5 0 00-7.54-.54l-3 3a5 5 0 007.07 7.07l1.71-1.71" />
             </svg>
           </div>
           <div className="min-w-0">
-            <div className="text-sm font-semibold text-white leading-tight truncate">KCG Connection</div>
-            <div className="text-[10px] text-gray-400 leading-tight truncate">Monitoring Service</div>
+            <div className="text-sm font-semibold text-[var(--color-text-primary)] leading-tight truncate">KCG Connection</div>
+            <div className="text-[10px] text-[var(--color-text-tertiary)] leading-tight truncate">Monitoring Service</div>
           </div>
         </div>
 
-        <nav className="flex-1 overflow-y-auto py-3 px-2 space-y-1 scrollbar-thin scrollbar-track-gray-900 scrollbar-thumb-gray-700">
+        <nav className="flex-1 overflow-y-auto py-3 px-2 space-y-1">
 
           {/* API Hub 바로가기 카드 */}
           <Link
             to="/api-hub"
-            className="flex items-center gap-3 mx-1 mb-3 px-3 py-2.5 rounded-lg border border-indigo-500/40 bg-indigo-500/10 hover:bg-indigo-500/20 transition-colors group"
+            className="flex items-center gap-3 mx-1 mb-3 px-3 py-2.5 rounded-lg border border-[var(--color-primary-active)] bg-[var(--color-primary-subtle)] hover:bg-[var(--color-primary-subtle)] transition-colors group"
           >
-            <div className="flex items-center justify-center w-7 h-7 rounded-md bg-indigo-600/30 flex-shrink-0">
-              <svg fill="none" viewBox="0 0 24 24" stroke="currentColor" strokeWidth={1.8} strokeLinecap="round" strokeLinejoin="round" width={15} height={15} className="text-indigo-300">
+            <div className="flex items-center justify-center w-7 h-7 rounded-md bg-[var(--color-primary-subtle)] flex-shrink-0">
+              <svg fill="none" viewBox="0 0 24 24" stroke="currentColor" strokeWidth={1.8} strokeLinecap="round" strokeLinejoin="round" width={15} height={15} className="text-[var(--color-primary)]">
                 <rect x="4" y="4" width="16" height="16" rx="2" />
                 <path d="M9 9h6M9 13h4" />
               </svg>
             </div>
             <div className="flex-1 min-w-0">
-              <div className="text-xs font-semibold text-indigo-300 leading-tight">API Hub</div>
-              <div className="text-[10px] text-indigo-400/70 leading-tight truncate">API 탐색 및 명세 확인</div>
+              <div className="text-xs font-semibold text-[var(--color-primary)] leading-tight">API Hub</div>
+              <div className="text-[10px] text-[var(--color-text-tertiary)] leading-tight truncate">API 탐색 및 명세 확인</div>
             </div>
-            <svg fill="none" viewBox="0 0 24 24" stroke="currentColor" strokeWidth={2} strokeLinecap="round" strokeLinejoin="round" width={14} height={14} className="text-indigo-400/60 flex-shrink-0 group-hover:text-indigo-300 transition-colors">
+            <svg fill="none" viewBox="0 0 24 24" stroke="currentColor" strokeWidth={2} strokeLinecap="round" strokeLinejoin="round" width={14} height={14} className="text-[var(--color-text-tertiary)] flex-shrink-0 group-hover:text-[var(--color-primary)] transition-colors">
               <path d="M9 18l6-6-6-6" />
             </svg>
           </Link>
@@ -242,15 +242,15 @@ const MainLayout = () => {
             className={({ isActive }) =>
               `relative flex items-center gap-2.5 px-3 py-2 rounded-lg text-sm transition-colors ${
                 isActive
-                  ? 'bg-gray-800 text-white'
-                  : 'text-gray-400 hover:bg-gray-800/60 hover:text-gray-200'
+                  ? 'bg-[var(--color-primary)] text-white dark:bg-[var(--color-primary-subtle)] dark:text-[var(--color-primary-text)]'
+                  : 'text-[var(--color-text-secondary)] hover:bg-[var(--color-primary-subtle)] hover:text-[var(--color-primary-text)]'
               }`
             }
           >
             {({ isActive }) => (
               <>
                 {isActive && (
-                  <span className="absolute left-0 top-1/2 -translate-y-1/2 w-0.5 h-5 bg-indigo-500 rounded-r-full" />
+                  <span className="absolute left-0 top-1/2 -translate-y-1/2 w-0.5 h-5 bg-[var(--color-primary)] rounded-r-full dark:hidden" />
                 )}
                 <span className="flex-shrink-0"><IconDashboard /></span>
                 <span className="font-medium">대시보드</span>
@@ -267,12 +267,12 @@ const MainLayout = () => {
             return (
               <div key={group.label}>
                 {/* 구분선 */}
-                <div className="my-2 mx-1 border-t border-gray-700/50" />
+                <div className="my-2 mx-1 border-t border-[var(--color-border)]" />
 
                 {/* 섹션 타이틀 */}
                 <button
                   onClick={() => toggleGroup(group.label)}
-                  className="flex w-full items-center justify-between px-3 py-1.5 text-[10px] font-semibold uppercase tracking-widest text-gray-500 hover:text-gray-300 transition-colors"
+                  className="flex w-full items-center justify-between px-3 py-1.5 text-[10px] font-semibold uppercase tracking-widest text-[var(--color-text-tertiary)] hover:text-[var(--color-text-secondary)] transition-colors"
                 >
                   <span>{group.label}</span>
                   <svg
@@ -302,15 +302,15 @@ const MainLayout = () => {
                           className={({ isActive }) =>
                             `relative flex items-center gap-2.5 px-3 py-2 rounded-lg text-sm transition-colors ${
                               isActive
-                                ? 'bg-gray-800 text-white'
-                                : 'text-gray-400 hover:bg-gray-800/60 hover:text-gray-200'
+                                ? 'bg-[var(--color-primary)] text-white dark:bg-[var(--color-primary-subtle)] dark:text-[var(--color-primary-text)]'
+                                : 'text-[var(--color-text-secondary)] hover:bg-[var(--color-primary-subtle)] hover:text-[var(--color-primary-text)]'
                             }`
                           }
                         >
                           {({ isActive }) => (
                             <>
                               {isActive && (
-                                <span className="absolute left-0 top-1/2 -translate-y-1/2 w-0.5 h-5 bg-indigo-500 rounded-r-full" />
+                                <span className="absolute left-0 top-1/2 -translate-y-1/2 w-0.5 h-5 bg-[var(--color-primary)] rounded-r-full dark:hidden" />
                               )}
                               <span className="flex-shrink-0">{item.icon}</span>
                               <span>{item.label}</span>
@@ -326,20 +326,20 @@ const MainLayout = () => {
           })}
 
           {/* 마지막 구분선 */}
-          <div className="my-2 mx-1 border-t border-gray-700/50" />
+          <div className="my-2 mx-1 border-t border-[var(--color-border)]" />
         </nav>
       </aside>
 
       {/* Main Content */}
       <div className="flex-1 ml-60">
         {/* Header */}
-        <header className="h-14 bg-gray-900 border-b border-gray-700/60 flex items-center justify-between px-6 sticky top-0 z-30">
+        <header className="h-14 bg-[var(--color-bg-surface)] border-b border-[var(--color-border)] flex items-center justify-between px-6 sticky top-0 z-30">
           <div />
           <div className="flex items-center gap-3">
             {/* 테마 토글 */}
             <button
               onClick={toggleTheme}
-              className="flex items-center justify-center w-8 h-8 rounded-lg text-gray-400 hover:text-gray-200 hover:bg-gray-800 transition-colors"
+              className="flex items-center justify-center w-8 h-8 rounded-lg text-[var(--color-text-secondary)] hover:text-[var(--color-text-primary)] hover:bg-[var(--color-bg-base)] transition-colors"
               title={theme === 'light' ? 'Dark mode' : 'Light mode'}
             >
               {theme === 'light' ? (
@@ -354,15 +354,15 @@ const MainLayout = () => {
             </button>
 
             {/* 역할 스위처 */}
-            <div className="flex items-center bg-gray-800 rounded-full p-0.5 gap-0.5">
+            <div className="flex items-center bg-[var(--color-bg-base)] border border-[var(--color-border)] rounded-full p-0.5 gap-0.5">
               {ROLES.map((role) => (
                 <button
                   key={role}
                   onClick={() => setRole(role)}
                   className={`px-3 py-1 text-xs font-medium rounded-full transition-colors ${
                     user?.role === role
-                      ? 'bg-indigo-600 text-white shadow-sm'
-                      : 'text-gray-400 hover:text-gray-200'
+                      ? 'bg-[var(--color-primary)] text-white shadow-sm dark:bg-[var(--color-primary-600)] dark:hover:bg-[var(--color-primary-500)]'
+                      : 'text-[var(--color-text-tertiary)] hover:text-[var(--color-text-secondary)]'
                   }`}
                 >
                   {role}
@@ -373,7 +373,7 @@ const MainLayout = () => {
         </header>
 
         {/* Content */}
-        <main className="p-6 bg-gray-100 dark:bg-gray-900 min-h-[calc(100vh-3.5rem)]">
+        <main className="p-6 bg-[var(--color-bg-base)] min-h-[calc(100vh-3.5rem)]">
           <Outlet />
         </main>
       </div>
diff --git a/frontend/src/pages/apihub/ApiHubDashboardPage.tsx b/frontend/src/pages/apihub/ApiHubDashboardPage.tsx
index 7ee4f35..bb3d5b9 100644
--- a/frontend/src/pages/apihub/ApiHubDashboardPage.tsx
+++ b/frontend/src/pages/apihub/ApiHubDashboardPage.tsx
@@ -128,7 +128,7 @@ const ApiHubDashboardPage = () => {
   if (isLoading) {
     return (
       <div className="flex items-center justify-center h-64">
-        <div className="text-gray-500 dark:text-gray-400">로딩 중...</div>
+        <div className="text-[var(--color-text-secondary)]">로딩 중...</div>
       </div>
     );
   }
@@ -136,10 +136,10 @@ const ApiHubDashboardPage = () => {
   return (
     <div className="max-w-7xl mx-auto space-y-8">
       {/* 히어로 배너 */}
-      <div className="relative overflow-hidden rounded-2xl bg-gradient-to-br from-indigo-950 via-indigo-800 to-indigo-600 p-8">
+      <div className="relative overflow-hidden rounded-2xl bg-gradient-to-br from-[var(--color-primary-950)] via-[var(--color-primary-800)] to-[var(--color-primary-600)] p-8">
         {/* 장식 글로우 원 */}
-        <div className="pointer-events-none absolute -right-16 -top-16 h-64 w-64 rounded-full bg-indigo-400 opacity-20 blur-3xl" />
-        <div className="pointer-events-none absolute right-32 -top-8 h-32 w-32 rounded-full bg-purple-400 opacity-10 blur-2xl" />
+        <div className="pointer-events-none absolute -right-16 -top-16 h-64 w-64 rounded-full bg-[var(--color-primary-400)] opacity-20 blur-3xl" />
+        <div className="pointer-events-none absolute right-32 -top-8 h-32 w-32 rounded-full bg-[var(--color-secondary-400)] opacity-10 blur-2xl" />
 
         {/* 제목 */}
         <h1 className="mb-2 text-4xl font-extrabold tracking-tight text-white">KCG API HUB</h1>
@@ -155,8 +155,8 @@ const ApiHubDashboardPage = () => {
                 <path fillRule="evenodd" d="M12.963 2.286a.75.75 0 00-1.071-.136 9.742 9.742 0 00-3.539 6.176 7.547 7.547 0 01-1.705-1.715.75.75 0 00-1.152-.082A9 9 0 1015.68 4.534a7.46 7.46 0 01-2.717-2.248zM15.75 14.25a3.75 3.75 0 11-7.313-1.172c.628.465 1.35.81 2.133 1a5.99 5.99 0 011.925-3.546 3.75 3.75 0 013.255 3.718z" clipRule="evenodd" />
               </svg>
             </div>
-            <h2 className="text-lg font-semibold text-gray-900 dark:text-gray-100">인기 API</h2>
-            <span className="ml-1 text-xs text-gray-400 dark:text-gray-500">최근 7일 기준</span>
+            <h2 className="text-lg font-semibold text-[var(--color-text-primary)]">인기 API</h2>
+            <span className="ml-1 text-xs text-[var(--color-text-tertiary)]">최근 7일 기준</span>
           </div>
           <div className="grid grid-cols-1 gap-4 sm:grid-cols-3">
             {popularApis.map((api, idx) => {
@@ -164,7 +164,7 @@ const ApiHubDashboardPage = () => {
               return (
                 <div
                   key={idx}
-                  className="group flex flex-col rounded-xl border border-gray-200 dark:border-gray-700 bg-white dark:bg-gray-800 p-5 shadow-sm cursor-pointer transition-all duration-200 hover:-translate-y-0.5 hover:shadow-md hover:border-indigo-400/50 dark:hover:border-indigo-500/50"
+                  className="group flex flex-col rounded-xl border border-[var(--color-border)] bg-[var(--color-bg-surface)] p-5 shadow-sm cursor-pointer transition-all duration-200 hover:-translate-y-0.5 hover:shadow-md hover:border-indigo-400/50"
                   onClick={() =>
                     api.serviceId && api.apiId
                       ? navigate(`/api-hub/services/${api.serviceId}/apis/${api.apiId}`)
@@ -187,17 +187,17 @@ const ApiHubDashboardPage = () => {
                     )}
                   </div>
                   <p
-                    className="flex-1 text-sm font-semibold text-gray-900 dark:text-gray-100 truncate mb-4"
+                    className="flex-1 text-sm font-semibold text-[var(--color-text-primary)] truncate mb-4"
                     title={api.apiName}
                   >
                     {api.apiName}
                   </p>
-                  <div className="flex items-end justify-between border-t border-gray-100 dark:border-gray-700 pt-3">
+                  <div className="flex items-end justify-between border-t border-[var(--color-border)] pt-3">
                     <div>
-                      <p className="text-xs text-gray-400 dark:text-gray-500 mb-0.5">주간 호출</p>
-                      <p className="text-xl font-bold text-gray-900 dark:text-gray-100">
+                      <p className="text-xs text-[var(--color-text-tertiary)] mb-0.5">주간 호출</p>
+                      <p className="text-xl font-bold text-[var(--color-text-primary)]">
                         {api.count.toLocaleString()}
-                        <span className="ml-0.5 text-xs font-normal text-gray-400 dark:text-gray-500">회</span>
+                        <span className="ml-0.5 text-xs font-normal text-[var(--color-text-tertiary)]">회</span>
                       </p>
                     </div>
                     <svg className="h-7 w-10 text-indigo-400/60" fill="none" viewBox="0 0 40 28" stroke="currentColor" strokeWidth={2} strokeLinecap="round" strokeLinejoin="round">
@@ -219,7 +219,7 @@ const ApiHubDashboardPage = () => {
               <path d="M9.813 15.904L9 18.75l-.813-2.846a4.5 4.5 0 00-3.09-3.09L2.25 12l2.846-.813a4.5 4.5 0 003.09-3.09L9 5.25l.813 2.846a4.5 4.5 0 003.09 3.09L15.75 12l-2.846.813a4.5 4.5 0 00-3.09 3.09zM18.259 8.715L18 9.75l-.259-1.035a3.375 3.375 0 00-2.455-2.456L14.25 6l1.036-.259a3.375 3.375 0 002.455-2.456L18 2.25l.259 1.035a3.375 3.375 0 002.455 2.456L21.75 6l-1.036.259a3.375 3.375 0 00-2.455 2.456z" />
             </svg>
           </div>
-          <h2 className="text-lg font-semibold text-gray-900 dark:text-gray-100">최신 등록 API</h2>
+          <h2 className="text-lg font-semibold text-[var(--color-text-primary)]">최신 등록 API</h2>
         </div>
         {recentTop3.length > 0 ? (
           <div className="grid grid-cols-1 gap-4 sm:grid-cols-3">
@@ -228,7 +228,7 @@ const ApiHubDashboardPage = () => {
               return (
                 <div
                   key={api.apiId}
-                  className="group flex flex-col rounded-xl border border-gray-200 dark:border-gray-700 bg-white dark:bg-gray-800 p-5 shadow-sm cursor-pointer transition-all duration-200 hover:-translate-y-0.5 hover:shadow-md hover:border-indigo-400/50 dark:hover:border-indigo-500/50"
+                  className="group flex flex-col rounded-xl border border-[var(--color-border)] bg-[var(--color-bg-surface)] p-5 shadow-sm cursor-pointer transition-all duration-200 hover:-translate-y-0.5 hover:shadow-md hover:border-indigo-400/50"
                   onClick={() => navigate(`/api-hub/services/${api.serviceId}/apis/${api.apiId}`)}
                 >
                   <div className="mb-2 flex items-center gap-2">
@@ -241,17 +241,17 @@ const ApiHubDashboardPage = () => {
                     )}
                   </div>
                   <p
-                    className="flex-1 text-sm font-semibold text-gray-900 dark:text-gray-100 mb-1 truncate"
+                    className="flex-1 text-sm font-semibold text-[var(--color-text-primary)] mb-1 truncate"
                     title={api.apiName}
                   >
                     {api.apiName}
                   </p>
                   {api.description && (
-                    <p className="mb-3 text-xs text-gray-500 dark:text-gray-400 line-clamp-2">
+                    <p className="mb-3 text-xs text-[var(--color-text-secondary)] line-clamp-2">
                       {truncate(api.description, 80)}
                     </p>
                   )}
-                  <div className="mt-auto flex items-center gap-1.5 text-xs text-gray-400 dark:text-gray-500">
+                  <div className="mt-auto flex items-center gap-1.5 text-xs text-[var(--color-text-tertiary)]">
                     <svg className="h-3.5 w-3.5 flex-shrink-0" fill="none" viewBox="0 0 24 24" stroke="currentColor">
                       <path
                         strokeLinecap="round"
@@ -267,7 +267,7 @@ const ApiHubDashboardPage = () => {
             })}
           </div>
         ) : (
-          <div className="rounded-xl border border-gray-200 dark:border-gray-700 bg-white dark:bg-gray-800 p-8 text-center text-sm text-gray-400 dark:text-gray-500">
+          <div className="rounded-xl border border-[var(--color-border)] bg-[var(--color-bg-surface)] p-8 text-center text-sm text-[var(--color-text-tertiary)]">
             등록된 API가 없습니다
           </div>
         )}
@@ -286,7 +286,7 @@ const ApiHubDashboardPage = () => {
                 />
               </svg>
             </div>
-            <h2 className="text-lg font-semibold text-gray-900 dark:text-gray-100">서비스 도메인</h2>
+            <h2 className="text-lg font-semibold text-[var(--color-text-primary)]">서비스 도메인</h2>
           </div>
           <div className="grid grid-cols-1 gap-4 sm:grid-cols-2 lg:grid-cols-3">
             {domainList.map((item) => {
@@ -297,9 +297,9 @@ const ApiHubDashboardPage = () => {
                 <div
                   key={item.domain}
                   onClick={() => navigate(`/api-hub/domains/${encodeURIComponent(item.domain)}`)}
-                  className={`group relative overflow-hidden rounded-xl border bg-white dark:bg-gray-800 ${palette.border} cursor-pointer transition-all duration-200 hover:-translate-y-1 hover:shadow-xl`}
+                  className={`group relative overflow-hidden rounded-xl border bg-[var(--color-bg-surface)] ${palette.border} cursor-pointer transition-all duration-200 hover:-translate-y-1 hover:shadow-xl`}
                 >
-                  <div className="relative h-[200px] overflow-hidden bg-gray-100 dark:bg-gray-700">
+                  <div className="relative h-[200px] overflow-hidden bg-[var(--color-bg-base)]">
                     <img
                       src={imgSrc}
                       alt={item.domain}
diff --git a/frontend/src/pages/monitoring/ServiceStatusPage.tsx b/frontend/src/pages/monitoring/ServiceStatusPage.tsx
index d56ce57..92ab883 100644
--- a/frontend/src/pages/monitoring/ServiceStatusPage.tsx
+++ b/frontend/src/pages/monitoring/ServiceStatusPage.tsx
@@ -57,14 +57,14 @@ const ServiceStatusPage = () => {
   const allOperational = services.length > 0 && services.every((s) => s.currentStatus === 'UP');
 
   if (isLoading) {
-    return <div className="text-center py-20 text-gray-500 dark:text-gray-400">로딩 중...</div>;
+    return <div className="text-center py-20 text-[var(--color-text-secondary)]">로딩 중...</div>;
   }
 
   return (
     <div className="max-w-7xl mx-auto">
       <div className="flex items-center justify-between mb-8">
-        <h1 className="text-2xl font-bold text-gray-900 dark:text-gray-100">Service Status</h1>
-        <span className="text-sm text-gray-500 dark:text-gray-400">마지막 갱신: {lastUpdated}</span>
+        <h1 className="text-2xl font-bold text-[var(--color-text-primary)]">Service Status</h1>
+        <span className="text-sm text-[var(--color-text-secondary)]">마지막 갱신: {lastUpdated}</span>
       </div>
 
       {/* Overall Status Banner */}
@@ -80,30 +80,30 @@ const ServiceStatusPage = () => {
       {/* Service List */}
       <div className="space-y-6">
         {services.map((svc) => (
-          <div key={svc.serviceId} className="bg-white dark:bg-gray-800 rounded-lg shadow">
+          <div key={svc.serviceId} className="bg-[var(--color-bg-surface)] rounded-lg shadow">
             {/* Service Header */}
-            <div className="p-6 border-b border-gray-200 dark:border-gray-700">
+            <div className="p-6 border-b border-[var(--color-border)]">
               <div className="flex items-center justify-between">
                 <div className="flex items-center gap-3">
                   <div className={`w-3 h-3 rounded-full ${STATUS_COLOR[svc.currentStatus] || 'bg-gray-400'}`} />
                   <h2
-                    className="text-lg font-semibold text-gray-900 dark:text-gray-100 cursor-pointer hover:text-blue-600"
+                    className="text-lg font-semibold text-[var(--color-text-primary)] cursor-pointer hover:text-[var(--color-primary)]"
                     onClick={() => navigate(`/monitoring/service-status/${svc.serviceId}`)}
                   >
                     {svc.serviceName}
                   </h2>
                 </div>
                 <div className="flex items-center gap-4">
-                  <span className={`text-sm font-medium ${svc.currentStatus === 'UP' ? 'text-green-600' : svc.currentStatus === 'DOWN' ? 'text-red-600' : 'text-gray-500'}`}>
+                  <span className={`text-sm font-medium ${svc.currentStatus === 'UP' ? 'text-green-600' : svc.currentStatus === 'DOWN' ? 'text-red-600' : 'text-[var(--color-text-secondary)]'}`}>
                     {STATUS_TEXT[svc.currentStatus] || svc.currentStatus}
                   </span>
                   {svc.lastResponseTime !== null && (
-                    <span className="text-sm text-gray-400">{svc.lastResponseTime}ms</span>
+                    <span className="text-sm text-[var(--color-text-tertiary)]">{svc.lastResponseTime}ms</span>
                   )}
                 </div>
               </div>
-              <div className="mt-1 text-sm text-gray-500 dark:text-gray-400">
-                90일 Uptime: <span className="font-medium text-gray-900 dark:text-gray-100">{svc.uptimePercent90d.toFixed(2)}%</span>
+              <div className="mt-1 text-sm text-[var(--color-text-secondary)]">
+                90일 Uptime: <span className="font-medium text-[var(--color-text-primary)]">{svc.uptimePercent90d.toFixed(2)}%</span>
               </div>
             </div>
 
@@ -128,10 +128,10 @@ const ServiceStatusPage = () => {
                     </div>
                   ))
                 ) : (
-                  <div className="flex-1 h-8 bg-gray-100 dark:bg-gray-700 rounded-sm" />
+                  <div className="flex-1 h-8 bg-[var(--color-bg-base)] rounded-sm" />
                 )}
               </div>
-              <div className="flex justify-between mt-1 text-xs text-gray-400 dark:text-gray-500">
+              <div className="flex justify-between mt-1 text-xs text-[var(--color-text-tertiary)]">
                 <span>{svc.dailyUptime.length > 0 ? formatDate(svc.dailyUptime[0].date) : ''}</span>
                 <span>Today</span>
               </div>
@@ -140,7 +140,7 @@ const ServiceStatusPage = () => {
         ))}
 
         {services.length === 0 && (
-          <div className="text-center py-20 text-gray-400 dark:text-gray-500">등록된 서비스가 없습니다</div>
+          <div className="text-center py-20 text-[var(--color-text-tertiary)]">등록된 서비스가 없습니다</div>
         )}
       </div>
     </div>
diff --git a/frontend/src/store/ThemeContext.tsx b/frontend/src/store/ThemeContext.tsx
index 3d7473c..50171f3 100644
--- a/frontend/src/store/ThemeContext.tsx
+++ b/frontend/src/store/ThemeContext.tsx
@@ -28,8 +28,10 @@ const ThemeProvider = ({ children }: ThemeProviderProps) => {
   useEffect(() => {
     if (theme === 'dark') {
       document.documentElement.classList.add('dark');
+      document.documentElement.classList.remove('light');
     } else {
       document.documentElement.classList.remove('dark');
+      document.documentElement.classList.add('light');
     }
     localStorage.setItem('theme', theme);
   }, [theme]);