diff --git a/src/common/config/public/ClientConfig.ts b/src/common/config/public/ClientConfig.ts
index 1e5bd0e6..d9dc95db 100644
--- a/src/common/config/public/ClientConfig.ts
+++ b/src/common/config/public/ClientConfig.ts
@@ -24,6 +24,11 @@ export enum ConfigPriority {
   basic = 0, advanced, underTheHood
 }
 
+
+export enum ThemeModes {
+  light = 1, dark, auto
+}
+
 export type TAGS = {
   client?: true,
   priority?: ConfigPriority,
@@ -500,6 +505,17 @@ export class ThemesConfig {
     description: $localize`Enable themes and color modes.`
   })
   enabled: boolean = false;
+
+  @ConfigProperty({
+    type: ThemeModes,
+    tags: {
+      name: $localize`Default theme mode`,
+      experimental: true,
+      uiDisabled: (sb: ThemesConfig) => !sb.enabled,
+    } as TAGS,
+    description: $localize`Sets the default theme mode that is used for the application.`
+  })
+  defaultMode: ThemeModes = ThemeModes.light;
 }
 
 
@@ -603,7 +619,7 @@ export class ClientGalleryConfig {
 
   @ConfigProperty({
     tags: {
-      name: $localize`ThemesConfig`,
+      name: $localize`Themes`,
       priority: ConfigPriority.advanced,
     },
   })
diff --git a/src/frontend/app/model/theme.service.ts b/src/frontend/app/model/theme.service.ts
index f97f7e78..f9100449 100644
--- a/src/frontend/app/model/theme.service.ts
+++ b/src/frontend/app/model/theme.service.ts
@@ -1,17 +1,24 @@
 import {Injectable} from '@angular/core';
 import {BehaviorSubject} from 'rxjs';
+import {ThemeModes} from '../../../common/config/public/ClientConfig';
 import {Config} from '../../../common/config/public/Config';
+import {GalleryCacheService} from '../ui/gallery/cache.gallery.service';
 
 
 @Injectable({
   providedIn: 'root'
 })
 export class ThemeService {
-  mode: ThemeMode = ThemeMode.light;
+  mode: ThemeModes = ThemeModes.light;
   public readonly darkMode: BehaviorSubject<boolean> = new BehaviorSubject(false);
   public readonly matcher = window.matchMedia('(prefers-color-scheme: dark)');
 
-  constructor() {
+  constructor(private cachingService: GalleryCacheService) {
+    if (cachingService.getThemeMode()) {
+      this.setMode(cachingService.getThemeMode());
+    } else {
+      this.setMode(Config.Gallery.Themes.defaultMode);
+    }
     this.darkMode.subscribe((darkMode: boolean) => {
         this.applyMode(darkMode);
       }
@@ -19,7 +26,7 @@ export class ThemeService {
   }
 
   listenToModePreference() {
-    if (this.mode !== ThemeMode.auto) {
+    if (this.mode !== ThemeModes.auto) {
       return;
     }
     this.darkMode.next(window.matchMedia('(prefers-color-scheme: dark)').matches);
@@ -44,39 +51,36 @@ export class ThemeService {
     }
   }
 
-  setMode(mode: ThemeMode) {
+  setMode(mode: ThemeModes) {
+    if (this.mode === mode) {
+      return;
+    }
     this.mode = mode;
-    if (this.mode === ThemeMode.light) {
+    if (this.mode === ThemeModes.light) {
       this.darkMode.next(false);
       this.stopListening();
-    } else if (this.mode === ThemeMode.dark) {
+    } else if (this.mode === ThemeModes.dark) {
       this.darkMode.next(true);
       this.stopListening();
-    } else if (this.mode === ThemeMode.auto) {
+    } else if (this.mode === ThemeModes.auto) {
       this.listenToModePreference();
     }
+    this.cachingService.setThemeMode(this.mode);
   }
 
 
   toggleMode() {
     switch (this.mode) {
-      case ThemeMode.light:
-        this.setMode(ThemeMode.dark);
+      case ThemeModes.light:
+        this.setMode(ThemeModes.dark);
         break;
-      case ThemeMode.dark:
-        this.setMode(ThemeMode.auto);
+      case ThemeModes.dark:
+        this.setMode(ThemeModes.auto);
         break;
-      case ThemeMode.auto:
-        this.setMode(ThemeMode.light);
+      case ThemeModes.auto:
+        this.setMode(ThemeModes.light);
         break;
     }
   }
 }
 
-export enum ThemeMode {
-  light = 1, dark, auto
-}
-
-export enum AppliedThemeMode {
-  light = 1, dark
-}
diff --git a/src/frontend/app/ui/gallery/cache.gallery.service.ts b/src/frontend/app/ui/gallery/cache.gallery.service.ts
index 20818b31..1fb6df1a 100644
--- a/src/frontend/app/ui/gallery/cache.gallery.service.ts
+++ b/src/frontend/app/ui/gallery/cache.gallery.service.ts
@@ -9,6 +9,7 @@ import {VersionService} from '../../model/version.service';
 import {SearchQueryDTO, SearchQueryTypes,} from '../../../../common/entities/SearchQueryDTO';
 import {ContentWrapper} from '../../../../common/entities/ConentWrapper';
 import {ContentWrapperWithError} from './content.service';
+import {ThemeModes} from '../../../../common/config/public/ClientConfig';
 
 interface CacheItem<T> {
   timestamp: number;
@@ -17,13 +18,14 @@ interface CacheItem<T> {
 
 @Injectable()
 export class GalleryCacheService {
-  private static readonly CONTENT_PREFIX = 'content:';
-  private static readonly AUTO_COMPLETE_PREFIX = 'autocomplete:';
-  private static readonly INSTANT_SEARCH_PREFIX = 'instant_search:';
-  private static readonly SEARCH_PREFIX = 'search:';
-  private static readonly SORTING_PREFIX = 'sorting:';
-  private static readonly VERSION = 'version';
-  private static readonly SLIDESHOW_SPEED = 'slideshow_speed';
+  private static readonly CONTENT_PREFIX = 'CONTENT:';
+  private static readonly AUTO_COMPLETE_PREFIX = 'AUTOCOMPLETE:';
+  private static readonly INSTANT_SEARCH_PREFIX = 'INSTANT_SEARCH:';
+  private static readonly SEARCH_PREFIX = 'SEARCH:';
+  private static readonly SORTING_PREFIX = 'SORTING:';
+  private static readonly VERSION = 'VERSION';
+  private static readonly SLIDESHOW_SPEED = 'SLIDESHOW_SPEED';
+  private static THEME_MODE = 'THEME_MODE';
 
   constructor(private versionService: VersionService) {
     // if it was a forced reload not a navigation, clear cache
@@ -315,4 +317,24 @@ export class GalleryCacheService {
       console.error(e);
     }
   }
+
+  getThemeMode(): ThemeModes {
+    const key = GalleryCacheService.THEME_MODE;
+    const tmp = localStorage.getItem(key) as keyof typeof ThemeModes;
+    if (tmp != null) {
+      return ThemeModes[tmp];
+    }
+    return null;
+  }
+
+
+  setThemeMode(mode: ThemeModes): void {
+    try {
+      const key = GalleryCacheService.THEME_MODE;
+      localStorage.setItem(key, ThemeModes[mode]);
+    } catch (e) {
+      this.reset();
+      console.error(e);
+    }
+  }
 }