What color should I paint my bedroom?

So, sadly I have to move out of my adorable brownstone parlor floor studio. I'm moving in with my friend and her fiance, and they were kind enough to give me the big bedroom. I'm already trying to figure out how I want to decorate! I've already begun saving for a lovely white upholstered headboard, as I've just been sleeping on a plain old mattress for a bed the last two years. I also plan on getting a charming white secretary style desk. The only thing I'm undecided on is what needs to come first--what color should I paint the walls? I only have one window, and we're on the ground floor, so I don't get the best light. I'm also going to be doing my work in the bedroom from time to time-- so I need to keep that in mind. Do you guys have a favorite bedroom color? Should I go for cool or warm? I'm leaning towards a light greyish-blue...

calming grey-blue





bright happy blues...




cozy neutral

the palest pink...

green and blue


or a gorgeous white bedroom...