You'll find 3 icons in the folder I linked to you by PM.
Normal state (with R letter inside).
Yellow-like icon for up to 3 alerts pending.
Red-like icon for more than 3 alerts pending.
All thos icons come with a "hover" version slightly enlighted to distinguish the difference as the mouse comes over.
Hope it will be cute
PS : Translation of the plugin is ALSO available in your MPs ;-)