diff --git a/src/common/dom/apply_themes_on_element.ts b/src/common/dom/apply_themes_on_element.ts
index cf431b6cb8..ee977cb498 100644
--- a/src/common/dom/apply_themes_on_element.ts
+++ b/src/common/dom/apply_themes_on_element.ts
@@ -61,11 +61,8 @@ export const applyThemesOnElement = (
     const accentColor = themeSettings?.accentColor;
 
     if (darkMode && primaryColor) {
-      themeRules["app-header-background-color"] = hexBlend(
-        primaryColor,
-        "#121212",
-        8
-      );
+      themeRules["app-theme-color"] = hexBlend(primaryColor, "#121212", 8);
+      themeRules["app-header-background-color"] = themeRules["app-theme-color"];
     }
 
     if (primaryColor) {