diff --git a/src/browser/themes/shared/customizableui/customizeMode-css.patch b/src/browser/themes/shared/customizableui/customizeMode-css.patch
new file mode 100644
index 000000000..dc21b6ecc
--- /dev/null
+++ b/src/browser/themes/shared/customizableui/customizeMode-css.patch
@@ -0,0 +1,13 @@
+diff --git a/browser/themes/shared/customizableui/customizeMode.css b/browser/themes/shared/customizableui/customizeMode.css
+index 6d318b05df9c48c8e6f50c5ac57a67a034dfdbc8..40eb134e0547aafc4304c4e401b36b6fa2362b07 100644
+--- a/browser/themes/shared/customizableui/customizeMode.css
++++ b/browser/themes/shared/customizableui/customizeMode.css
+@@ -28,7 +28,7 @@ toolbar[overflowable][customizing] > .customization-target {
+ #customization-container {
+   flex-direction: column;
+   min-height: 0;
+-  background-color: var(--toolbar-bgcolor);
++  background-color: light-dark(#f9f9fb, rgb(43, 42, 51));
+   color: var(--toolbar-color);
+   color-scheme: var(--toolbar-color-scheme);
+