diff --git a/userChrome.css b/userChrome.css
index 2325c99..04294b8 100644
--- a/userChrome.css
+++ b/userChrome.css
@@ -23,6 +23,14 @@
     border-radius: 4px;
   }
 
+  /*= Icon Fill Color ========================================================*/
+  :root:-moz-lwtheme {
+    /* Auto create --lwt-toolbarbutton-icon-fill-attention, fix for nightly default theme
+       Default Color: rgb(0,97,224) -> rgb(0, 120, 215) for more light
+     */
+    --lwt-toolbarbutton-icon-fill-attention: var(--button-primary-bgcolor, rgb(0, 120, 215));
+  }
+
   /*= Light Weight Theme =====================================================*/
   /* Header Image */
   :root[lwtheme-image] {