diff --git a/config/kibana.yml b/config/kibana.yml
index a37c740ebab07..c816337f881d4 100644
--- a/config/kibana.yml
+++ b/config/kibana.yml
@@ -1,8 +1,6 @@
 # For more configuration options see the configuration guide for Kibana in
 # https://www.elastic.co/guide/index.html
 
-uiSettings.experimental.themeSwitcherEnabled: true
-
 # =================== System: Kibana Server ===================
 # Kibana is served by a back end server. This setting specifies the port to use.
 #server.port: 5601
diff --git a/packages/core/ui-settings/core-ui-settings-common/src/theme.ts b/packages/core/ui-settings/core-ui-settings-common/src/theme.ts
index 73b465d5b192f..d8a3be5ee79d4 100644
--- a/packages/core/ui-settings/core-ui-settings-common/src/theme.ts
+++ b/packages/core/ui-settings/core-ui-settings-common/src/theme.ts
@@ -35,7 +35,7 @@ export type ThemeTags = readonly ThemeTag[];
  * An array of theme tags available in Kibana by default when not customized
  * using KBN_OPTIMIZER_THEMES environment variable.
  */
-export const DEFAULT_THEME_TAGS: ThemeTags = ThemeAmsterdamTags;
+export const DEFAULT_THEME_TAGS: ThemeTags = SUPPORTED_THEME_TAGS;
 
 export const FALLBACK_THEME_TAG: ThemeTag = 'v8light';
 
diff --git a/packages/core/ui-settings/core-ui-settings-server-internal/src/settings/theme.ts b/packages/core/ui-settings/core-ui-settings-server-internal/src/settings/theme.ts
index a7249224ad9ee..904f2463557b6 100644
--- a/packages/core/ui-settings/core-ui-settings-server-internal/src/settings/theme.ts
+++ b/packages/core/ui-settings/core-ui-settings-server-internal/src/settings/theme.ts
@@ -24,6 +24,7 @@ function getThemeInfo(options: GetThemeSettingsOptions) {
   }
 
   const themeTags = parseThemeTags('experimental');
+  // const themeTags = parseThemeTags(process.env.KBN_OPTIMIZER_THEMES);
   return {
     defaultDarkMode: themeTags[0].endsWith('dark'),
   };
@@ -104,9 +105,9 @@ export const getThemeSettings = (
         }),
       },
       value: 'amsterdam',
-      readonly: Object.hasOwn(options, 'isThemeSwitcherEnabled')
-        ? !options.isThemeSwitcherEnabled
-        : true,
+      // readonly: Object.hasOwn(options, 'isThemeSwitcherEnabled')
+      //   ? !options.isThemeSwitcherEnabled
+      //   : true,
       requiresPageReload: true,
       schema: schema.oneOf([
         schema.literal('amsterdam'),
diff --git a/packages/core/ui-settings/core-ui-settings-server-internal/src/ui_settings_service.ts b/packages/core/ui-settings/core-ui-settings-server-internal/src/ui_settings_service.ts
index 70c880c85594f..fd13744044c77 100644
--- a/packages/core/ui-settings/core-ui-settings-server-internal/src/ui_settings_service.ts
+++ b/packages/core/ui-settings/core-ui-settings-server-internal/src/ui_settings_service.ts
@@ -68,13 +68,13 @@ export class UiSettingsService
   public async preboot(): Promise<InternalUiSettingsServicePreboot> {
     this.log.debug('Prebooting ui settings service');
 
-    const { overrides, experimental } = await firstValueFrom(this.config$);
+    const { overrides } = await firstValueFrom(this.config$);
     this.overrides = overrides;
 
     this.register(
       getCoreSettings({
         isDist: this.isDist,
-        isThemeSwitcherEnabled: experimental?.themeSwitcherEnabled,
+        isThemeSwitcherEnabled: true,
       })
     );
 
diff --git a/packages/kbn-optimizer/src/optimizer/optimizer_config.ts b/packages/kbn-optimizer/src/optimizer/optimizer_config.ts
index 5274e95cf8646..8014d62cd93f8 100644
--- a/packages/kbn-optimizer/src/optimizer/optimizer_config.ts
+++ b/packages/kbn-optimizer/src/optimizer/optimizer_config.ts
@@ -152,6 +152,9 @@ export class OptimizerConfig {
     }
 
     const themeTags = parseThemeTags('experimental');
+    // const themeTags = parseThemeTags(
+    //   options.themes || (dist ? '*' : process.env.KBN_OPTIMIZER_THEMES)
+    // );
 
     const pluginPaths = options.pluginPaths;
     if (
diff --git a/scripts/build.js b/scripts/build.js
index 191444dc817b6..88a8cc2a78705 100644
--- a/scripts/build.js
+++ b/scripts/build.js
@@ -6,7 +6,6 @@
  * your election, the "Elastic License 2.0", the "GNU Affero General Public
  * License v3.0 only", or the "Server Side Public License, v 1".
  */
-process.env.KBN_OPTIMIZER_THEMES = 'experimental';
 
 require('../src/setup_node_env');
 require('../src/dev/build/cli');
diff --git a/scripts/kibana.js b/scripts/kibana.js
index 57aca2323c4dd..75d87593829fd 100644
--- a/scripts/kibana.js
+++ b/scripts/kibana.js
@@ -7,6 +7,4 @@
  * License v3.0 only", or the "Server Side Public License, v 1".
  */
 
-process.env.KBN_OPTIMIZER_THEMES = 'experimental';
-
 require('../src/cli/dev');