Bringing color into a room by painting furniture (instead of walls):
Cover unsightly open sinks--and even small vanities--with a skirt. I'd remove any doors on the vanity, and stash them for later re-install, to make access to storage through the cloth easier.
Installing large drapes or curtains over an entire wall not only adds personality and color, it can help diminish outside street noises and it creates an illusion that a window is much larger than it really is.
For the rest of the decor ideas to make your apartment fabulous, read the full article at BHG:
24 Ideas to Steal for Your Apartment [Better Homes and Gardens]