You don't need to paint a wall, just check out some of the results from
THIS SEARCH. I always used to live in places with simple white walls and black leather furniture, and then add lots of color by what I put in the rooms and on the walls. The nice part is that it's easy to change things up by swapping things.
Now, the trend seems to be to paint one wall some color (often antique red) while leaving the others as some type of white or off-white.
Ah, forgot to mention that I also had all sorts of lighting including different colors for easy mood adjustment. Of course, I used to have a huge 18' x 28' bedroom at one place that doubled as a "test" underground club as well as a nearly self-contained apartment - heh. How many others have a bedroom complete with fog machines, beamer lights, strobe lights, lasers, rope lights, black lights, etc.? Boy those were fun days...