Thanks man, thats really kind of you. I think Velvet blue (#162252) is the best for what I'd like to see. Could you apply it to the Login screen like you have with haunter. I know hes not blue but it would be badass to me.
(Edit)
After relooking how you did the background I decided telling you one color probably wasn't specific enough. So if you look at the way you did it in the screen shots while a window is open, the headers are a lighter shade while the window is a darker blacker purple. So I'd say "Blue Velvet(#162252)" for the background or "darker shade" and maybe just "midnightblue(#191970)" for the headers. But honestly I dunno how you did it I'm just taking a guess that you might need two colors. I don't know if its possible to redo the login screen real easy.