When I first saw cmus screenshot on its website, I wanted to download it right away. Unfortunately, there's no theme like that available (at least not one that is independent of your terminal color settings). So I made one myself!
IMPORTANT: this will only work on terminals that support 256 colors
NOTE: as someone from the cmus-devel mailing list pointed out, the theme on the screenshot is zenburn*, which is available here and should ship with cmus on upcoming releases.*
Just drop screenshot.theme on ~/.cmus and run :colorscheme screenshot.