Menus background-color should differ from the actionmenu background-color

When creating and using menus, it is better to visually differentiate them from the general actionmenu. An example of a menu that has a different color is used on xwiki.org, see image

Currently the both menus are using the colors from the NavBar. An idea would be to use the colors from the Inverted Navbar. We could adjust the default color theme and provide a nice contrast / balance for these two versions of the menus.