--- a/browser/themes/shared/customizableui/customizeMode.inc.css
+++ b/browser/themes/shared/customizableui/customizeMode.inc.css
@@ -251,24 +251,26 @@ toolbarpaletteitem[place="toolbar"]:not(
 
 toolbarpaletteitem[place="toolbar"]:not([mousedown="true"]):-moz-focusring {
   outline-offset: -5px;
 }
 
 toolbarpaletteitem[place=palette] > toolbarspring {
   width: 7em;
   min-width: 7em;
-  outline: 1px solid GrayText;
+  outline: 1px solid;
   outline-offset: -8px;
+  opacity: .6;
   height: 37px;
 }
 
 toolbarpaletteitem[place=toolbar] > toolbarspring {
-  outline: 1px solid GrayText;
+  outline: 1px solid;
   outline-offset: -2px;
+  opacity: .6;
   margin-top: 5px;
   margin-bottom: 5px;
 }
 
 #wrapper-edit-controls > #edit-controls > toolbarbutton > .toolbarbutton-icon {
   opacity: 1; /* To ensure these buttons always look enabled in customize mode */
 }