Rules for disabled menu items.

xpfe/global/resources/skin/xul.css

@@ -273,11 +273,19 @@ xpmenu {
 	font: inherit;
 }
 
+xpmenu[disabled="true"] {
+	color: #999999;
+}
+
 xpmenuitem {
 	display: block;
 	font: inherit;
 }
 
+xpmenuitem[disabled="true"] {
+	color: #999999;
+}
+
 xpmenuchildren {
   display: block;
   font: inherit;