diff --git a/frontend/src/app/AppLayout.jsx b/frontend/src/app/AppLayout.jsx
index 062ce6d..98fc74c 100644
--- a/frontend/src/app/AppLayout.jsx
+++ b/frontend/src/app/AppLayout.jsx
@@ -28,7 +28,6 @@ const DEFAULT_FOLDER_NAME = 'Documents';
 const ROW_KEY_SEPARATOR = ':';
 const DOCUMENT_ROW_PREFIX = 'document';
 const FOLDER_ROW_PREFIX = 'folder';
-const THEME_STORAGE_KEY = 'papercrate_theme_settings';
 
 const resolveApiPath = (path = '') => path;
 
@@ -199,66 +198,6 @@ const AppLayout = () => {
   });
   const lastNonDeskViewRef = useRef(documentsViewMode === 'desk' ? 'list' : documentsViewMode);
 
-  const loadThemeSettings = () => {
-    const defaults = { neutralHue: 260, mode: 'system' };
-    if (typeof window === 'undefined') {
-      if (typeof document !== 'undefined') {
-        const current = document.documentElement.style.getPropertyValue('--neutral-hue');
-        const parsed = Number.parseInt(current, 10);
-        return {
-          neutralHue: Number.isNaN(parsed) ? defaults.neutralHue : parsed,
-          mode: defaults.mode,
-        };
-      }
-      return defaults;
-    }
-
-    const root = document.documentElement;
-    const loadFromRoot = () => {
-      const current = root.style.getPropertyValue('--neutral-hue');
-      const parsed = Number.parseInt(current, 10);
-      return Number.isNaN(parsed) ? defaults.neutralHue : parsed;
-    };
-
-    let neutralHueValue = loadFromRoot();
-    let modeValue = defaults.mode;
-
-    const composite = window.localStorage.getItem(THEME_STORAGE_KEY);
-    if (composite) {
-      try {
-        const parsed = JSON.parse(composite);
-        const storedHue = Number.parseInt(parsed?.neutralHue, 10);
-        if (!Number.isNaN(storedHue)) {
-          neutralHueValue = storedHue;
-        }
-        const storedMode = parsed?.mode;
-        if (storedMode === 'light' || storedMode === 'dark' || storedMode === 'system') {
-          modeValue = storedMode;
-        }
-      } catch (error) {
-        console.warn('[theme] failed to parse stored theme settings', error);
-      }
-    } else {
-      const legacyHue = window.localStorage.getItem('papercrate_neutral_hue');
-      if (legacyHue) {
-        const parsedLegacyHue = Number.parseInt(legacyHue, 10);
-        if (!Number.isNaN(parsedLegacyHue)) {
-          neutralHueValue = parsedLegacyHue;
-        }
-      }
-      const legacyMode = window.localStorage.getItem('papercrate_theme_mode');
-      if (legacyMode === 'light' || legacyMode === 'dark' || legacyMode === 'system') {
-        modeValue = legacyMode;
-      }
-    }
-
-    return { neutralHue: neutralHueValue, mode: modeValue };
-  };
-
-  const initialThemeSettings = loadThemeSettings();
-  const [neutralHue, setNeutralHue] = useState(initialThemeSettings.neutralHue);
-  const [themeMode, setThemeMode] = useState(initialThemeSettings.mode);
-
   useEffect(() => {
     if (documentsViewMode !== 'desk') {
       lastNonDeskViewRef.current = documentsViewMode;
@@ -363,56 +302,6 @@ const AppLayout = () => {
     }
   }, [token, appStatus, refreshAccessToken]);
 
-  useEffect(() => {
-    if (typeof document !== 'undefined') {
-      document.documentElement.style.setProperty('--neutral-hue', `${neutralHue}deg`);
-    }
-  }, [neutralHue]);
-
-  useEffect(() => {
-    if (typeof document !== 'undefined') {
-      const root = document.documentElement;
-      if (themeMode === 'system') {
-        root.removeAttribute('data-theme');
-      } else {
-        root.setAttribute('data-theme', themeMode);
-      }
-    }
-  }, [themeMode]);
-
-  useEffect(() => {
-    if (typeof window === 'undefined') {
-      return;
-    }
-    try {
-      const payload = JSON.stringify({ neutralHue, mode: themeMode });
-      window.localStorage.setItem(THEME_STORAGE_KEY, payload);
-      window.localStorage.removeItem('papercrate_neutral_hue');
-      window.localStorage.removeItem('papercrate_theme_mode');
-    } catch (error) {
-      console.warn('[theme] failed to persist theme settings', error);
-    }
-  }, [neutralHue, themeMode]);
-
-  const handleNeutralHueChange = useCallback((value) => {
-    if (value === '') {
-      setNeutralHue(180);
-      return;
-    }
-    const parsed = Number(value);
-    if (Number.isNaN(parsed)) {
-      return;
-    }
-    setNeutralHue(parsed);
-  }, []);
-
-  const handleThemeModeChange = useCallback((mode) => {
-    if (mode !== 'light' && mode !== 'dark' && mode !== 'system') {
-      return;
-    }
-    setThemeMode(mode);
-  }, []);
-
   const clearFilters = useCallback(() => {
     setSearchQuery('');
     setActiveTagFilters([]);
@@ -5084,10 +4973,6 @@ const AppLayout = () => {
       draggedFolderId,
       onCreateFolder: handlePromptCreateFolder,
       creatingFolder,
-      onNeutralHueChange: handleNeutralHueChange,
-      neutralHue,
-      themeMode,
-      onThemeModeChange: handleThemeModeChange,
       tags,
       activeTagIds: activeTagFilters,
       onToggleTagFilter: toggleTagFilter,
@@ -5146,10 +5031,6 @@ const AppLayout = () => {
       handleCorrespondentCreate,
       handlePromptCreateFolder,
       creatingFolder,
-      handleNeutralHueChange,
-      neutralHue,
-      themeMode,
-      handleThemeModeChange,
     ],
   );
 
diff --git a/frontend/src/sidebar/Sidebar.jsx b/frontend/src/sidebar/Sidebar.jsx
index 212535d..c344e2c 100644
--- a/frontend/src/sidebar/Sidebar.jsx
+++ b/frontend/src/sidebar/Sidebar.jsx
@@ -157,10 +157,6 @@ const Sidebar = ({
   draggedFolderId,
   onCreateFolder,
   creatingFolder = false,
-  onNeutralHueChange,
-  neutralHue,
-  themeMode = 'system',
-  onThemeModeChange,
   tags = [],
   activeTagIds = [],
   onToggleTagFilter,
@@ -184,7 +180,15 @@ const Sidebar = ({
   onSelectTenant,
   onOpenSettings,
 }) => {
-  const { setCollapsed } = useSidebarContext();
+  const {
+    setCollapsed,
+    neutralHue,
+    setNeutralHue,
+    resetNeutralHue,
+    themeMode,
+    cycleThemeMode,
+    themeModes,
+  } = useSidebarContext();
   const handleCollapse = useCallback(() => {
     setCollapsed(true);
   }, [setCollapsed]);
@@ -246,15 +250,31 @@ const Sidebar = ({
   }, [creatingFolder, onCreateFolder]);
 
   const handleNeutralHueReset = useCallback(() => {
-    onNeutralHueChange?.('');
-  }, [onNeutralHueChange]);
+    resetNeutralHue();
+  }, [resetNeutralHue]);
 
-  const themeModeIndex = THEME_MODES.indexOf(themeMode);
+  const handleNeutralHueChange = useCallback(
+    (value) => {
+      if (value === '') {
+        resetNeutralHue();
+        return;
+      }
+      const parsed = Number(value);
+      if (Number.isNaN(parsed)) {
+        return;
+      }
+      setNeutralHue(parsed);
+    },
+    [resetNeutralHue, setNeutralHue],
+  );
+
+  const themeModeList = themeModes && themeModes.length ? themeModes : THEME_MODES;
+  const themeModeIndex = themeModeList.indexOf(themeMode);
   const safeThemeModeIndex = themeModeIndex === -1 ? 0 : themeModeIndex;
-  const resolvedThemeMode = THEME_MODES[safeThemeModeIndex];
-  const nextThemeMode = THEME_MODES[(safeThemeModeIndex + 1) % THEME_MODES.length];
-  const themeModeLabel = THEME_MODE_LABELS[resolvedThemeMode];
-  const nextThemeLabel = THEME_MODE_LABELS[nextThemeMode];
+  const resolvedThemeMode = themeModeList[safeThemeModeIndex] || THEME_MODES[0];
+  const nextThemeMode = themeModeList[(safeThemeModeIndex + 1) % themeModeList.length];
+  const themeModeLabel = THEME_MODE_LABELS[resolvedThemeMode] || THEME_MODE_LABELS.system;
+  const nextThemeLabel = THEME_MODE_LABELS[nextThemeMode] || THEME_MODE_LABELS.system;
   const themeModeIcon = resolvedThemeMode === 'dark'
     ? <MoonIcon size={16} />
     : resolvedThemeMode === 'light'
@@ -262,14 +282,8 @@ const Sidebar = ({
       : <DesktopIcon size={16} />;
 
   const handleThemeModeToggle = useCallback(() => {
-    if (!onThemeModeChange) {
-      return;
-    }
-    const currentIndex = THEME_MODES.indexOf(themeMode);
-    const safeIndex = currentIndex === -1 ? 0 : currentIndex;
-    const nextMode = THEME_MODES[(safeIndex + 1) % THEME_MODES.length];
-    onThemeModeChange(nextMode);
-  }, [onThemeModeChange, themeMode]);
+    cycleThemeMode();
+  }, [cycleThemeMode]);
 
   const handleSearchInputChange = useCallback(
     (event) => {
@@ -415,7 +429,7 @@ const Sidebar = ({
                 max="360"
                 step="1"
                 value={neutralHue}
-                onChange={(event) => onNeutralHueChange?.(event.target.value)}
+                onChange={(event) => handleNeutralHueChange(event.target.value)}
               />
               <span className="sidebar-slider__value">{neutralHue}°</span>
             </label>
diff --git a/frontend/src/sidebar/SidebarContext.js b/frontend/src/sidebar/SidebarContext.js
index cfbe5e5..a609db3 100644
--- a/frontend/src/sidebar/SidebarContext.js
+++ b/frontend/src/sidebar/SidebarContext.js
@@ -1,11 +1,161 @@
-import React, { createContext, useContext, useMemo, useState, useCallback } from 'react';
+import React, {
+  createContext,
+  useContext,
+  useMemo,
+  useState,
+  useCallback,
+  useEffect,
+} from 'react';
 
 const SidebarContext = createContext(null);
 
+const THEME_STORAGE_KEY = 'papercrate_theme_settings';
+const DEFAULT_NEUTRAL_HUE = 180;
+const DEFAULT_THEME_MODE = 'system';
+const THEME_MODES = ['system', 'light', 'dark'];
+
+const loadInitialThemeSettings = () => {
+  const defaults = { neutralHue: DEFAULT_NEUTRAL_HUE, mode: DEFAULT_THEME_MODE };
+
+  if (typeof window === 'undefined') {
+    if (typeof document !== 'undefined') {
+      const current = document.documentElement.style.getPropertyValue('--neutral-hue');
+      const parsed = Number.parseInt(current, 10);
+      return {
+        neutralHue: Number.isNaN(parsed) ? defaults.neutralHue : parsed,
+        mode: defaults.mode,
+      };
+    }
+    return defaults;
+  }
+
+  const root = document.documentElement;
+  const loadFromRoot = () => {
+    const current = root.style.getPropertyValue('--neutral-hue');
+    const parsed = Number.parseInt(current, 10);
+    return Number.isNaN(parsed) ? defaults.neutralHue : parsed;
+  };
+
+  let neutralHueValue = loadFromRoot();
+  let modeValue = defaults.mode;
+
+  const composite = window.localStorage.getItem(THEME_STORAGE_KEY);
+  if (composite) {
+    try {
+      const parsed = JSON.parse(composite);
+      const storedHue = Number.parseInt(parsed?.neutralHue, 10);
+      if (!Number.isNaN(storedHue)) {
+        neutralHueValue = storedHue;
+      }
+      const storedMode = parsed?.mode;
+      if (THEME_MODES.includes(storedMode)) {
+        modeValue = storedMode;
+      }
+    } catch (error) {
+      console.warn('[theme] failed to parse stored theme settings', error);
+    }
+  } else {
+    const legacyHue = window.localStorage.getItem('papercrate_neutral_hue');
+    if (legacyHue) {
+      const parsedLegacyHue = Number.parseInt(legacyHue, 10);
+      if (!Number.isNaN(parsedLegacyHue)) {
+        neutralHueValue = parsedLegacyHue;
+      }
+    }
+    const legacyMode = window.localStorage.getItem('papercrate_theme_mode');
+    if (THEME_MODES.includes(legacyMode)) {
+      modeValue = legacyMode;
+    }
+  }
+
+  return { neutralHue: neutralHueValue, mode: modeValue };
+};
+
 export const SidebarProvider = ({ initialCollapsed = false, children }) => {
   const [collapsed, setCollapsed] = useState(initialCollapsed);
+  const initialTheme = useMemo(() => loadInitialThemeSettings(), []);
+  const [neutralHue, setNeutralHueState] = useState(initialTheme.neutralHue);
+  const [themeMode, setThemeModeState] = useState(initialTheme.mode);
 
-  const contextValue = useMemo(() => ({ collapsed, setCollapsed }), [collapsed]);
+  useEffect(() => {
+    if (typeof document === 'undefined') {
+      return;
+    }
+    document.documentElement.style.setProperty('--neutral-hue', `${neutralHue}deg`);
+  }, [neutralHue]);
+
+  useEffect(() => {
+    if (typeof document === 'undefined') {
+      return;
+    }
+    const root = document.documentElement;
+    if (themeMode === 'system') {
+      root.removeAttribute('data-theme');
+    } else {
+      root.setAttribute('data-theme', themeMode);
+    }
+  }, [themeMode]);
+
+  useEffect(() => {
+    if (typeof window === 'undefined') {
+      return;
+    }
+    try {
+      const payload = JSON.stringify({ neutralHue, mode: themeMode });
+      window.localStorage.setItem(THEME_STORAGE_KEY, payload);
+      window.localStorage.removeItem('papercrate_neutral_hue');
+      window.localStorage.removeItem('papercrate_theme_mode');
+    } catch (error) {
+      console.warn('[theme] failed to persist theme settings', error);
+    }
+  }, [neutralHue, themeMode]);
+
+  const setNeutralHue = useCallback((value) => {
+    setNeutralHueState((prev) => {
+      if (value === '' || value === null || typeof value === 'undefined') {
+        return DEFAULT_NEUTRAL_HUE;
+      }
+      const parsed = Number(value);
+      if (Number.isNaN(parsed)) {
+        return prev;
+      }
+      const clamped = Math.min(Math.max(Math.round(parsed), 0), 360);
+      return clamped;
+    });
+  }, []);
+
+  const resetNeutralHue = useCallback(() => {
+    setNeutralHueState(DEFAULT_NEUTRAL_HUE);
+  }, []);
+
+  const setThemeMode = useCallback((mode) => {
+    if (!THEME_MODES.includes(mode)) {
+      return;
+    }
+    setThemeModeState(mode);
+  }, []);
+
+  const cycleThemeMode = useCallback(() => {
+    const index = THEME_MODES.indexOf(themeMode);
+    const nextIndex = index === -1 ? 0 : (index + 1) % THEME_MODES.length;
+    setThemeModeState(THEME_MODES[nextIndex]);
+  }, [themeMode]);
+
+  const contextValue = useMemo(
+    () => ({
+      collapsed,
+      setCollapsed,
+      neutralHue,
+      setNeutralHue,
+      resetNeutralHue,
+      themeMode,
+      setThemeMode,
+      cycleThemeMode,
+      themeModes: THEME_MODES,
+      defaultNeutralHue: DEFAULT_NEUTRAL_HUE,
+    }),
+    [collapsed, neutralHue, setNeutralHue, resetNeutralHue, themeMode, setThemeMode, cycleThemeMode],
+  );
 
   return <SidebarContext.Provider value={contextValue}>{children}</SidebarContext.Provider>;
 };