"The above images are straight from the source files of the Zune Software. You can check yourself using PE Explorer. The above colors are as follows from left to right: Magenta, Pink, Purple, and then Atomic (looks to be orange)"
Hopefully this will put to rest some concerns about the current lineup of Zune HD color options. The Atomic looks particularly cool, and I really hope to see these on shelves sooner rather than later.