Selecting a custom color scheme for "Top Bar Menu Selected Background" will change the color of "Browse" and "username" drop down menus when a mouse hover into them. But this does not apply to the notification icon. The background color of the notification icon does not change when hovering into the icon

Steps to reproduce

1. Go to Confluence Admin > Color Scheme > Edit
2. Set "Top Bar Menu Selected Background" to #cc0000

Hovering to "Browse" and username menus will change the background color to red, but not for the notification icon.

Workaround

Add the following CSS to Confluence Admin > Stylesheet

#notifications-anchor.active, #notifications-anchor:hover {
background-color: #cc0000;
}

NOTE: This workaround only works outside of Confluence Admin