We just started with XWiki and enjoy the experienence so far.
With the Menu-Extension ( Menu Application (XWiki.org)), we implemented a horizontal menu, which works fine. Now we´re wondering, whether it is possible to give the menu-bar another color.
Our brand-color is kind of dominant and the header gets way to massive. A little more gray within the navigation-bar would do the trick.
You can probably either use the @lessCode variable exposed in the advanced section of your color theme, or use a skin extension to make sure your CSS is loaded only when the menu is.
From there you’re only a couple lines of CSS from the solution, probably something close to