--- a/browser/themes/shared/customizableui/panelUI.inc.css
+++ b/browser/themes/shared/customizableui/panelUI.inc.css
@@ -1174,16 +1174,21 @@ toolbarpaletteitem[place="palette"] > #s
 }
 
 /* In customize mode, extend the buttons *only* in the panel, just to make them not look stupid */
 toolbarpaletteitem[place="menu-panel"] > .toolbaritem-combined-buttons > toolbarbutton {
   min-width: calc(@menuPanelButtonWidth@ - 1px);
   max-width: calc(@menuPanelButtonWidth@ - 1px);
 }
 
+.toolbaritem-combined-buttons@inAnyPanel@ > toolbarbutton[disabled] {
+  /* Override toolbarbutton.css which sets the color to GrayText */
+  color: inherit;
+}
+
 #main-window:not([customizing]) .toolbaritem-combined-buttons@inAnyPanel@ > toolbarbutton[disabled] > .toolbarbutton-icon {
   opacity: .25;
 }
 
 #zoom-controls[cui-areatype="toolbar"] > #zoom-reset-button > .toolbarbutton-text {
 %ifdef XP_MACOSX
   min-width: 6ch;
 %else