--- a/mail/themes/pinstripe/mail/quickFilterBar.css
+++ b/mail/themes/pinstripe/mail/quickFilterBar.css
@@ -41,16 +41,22 @@ toolbar[iconsize="large"] #qfb-show-filt
   background-color: rgba(0, 0, 0, 0.2);
   border-color: transparent;
   border-radius: 4px;
   box-shadow: 0 1px rgba(0, 0, 0, 0.4) inset, 1px 0 rgba(0, 0, 0, 0.3) inset,
               0 1px rgba(255, 255, 255, 0.5);
   text-shadow: 0 1px rgba(0, 0, 0, 0.4) !important;
 }
 
+#mail-toolbox #qfb-show-filter-bar[checked="true"]:-moz-lwtheme {
+  color: inherit !important;
+  background-color: rgba(0, 0, 0, 0.15);
+  text-shadow: inherit !important;
+}
+
 /* :::: Filter Bar :::: */
 
 #quick-filter-bar {
   height: 25px;
 }
 
 #quick-filter-bar-main-bar {
   background: -moz-linear-gradient(top, #eaeaea, #d1d1d1);