HTML5 - changed arrow color of presentation

bigbluebutton-html5/imports/ui/components/whiteboard/slide-controls/styles.scss

@@ -34,10 +34,9 @@ $controls-background: #F0F2F6 !default;
     height: 2.25rem;
   }
 
-  button {
-    i {
-      font-weight: bolder;
-    }
+  i {
+    font-weight: bolder;
+    color: $color-gray;
   }
 }