I always wanted a dark, soothing bedroom. When I moved into my first post-college apartment, I went for it. I picked Behr "Paramount" off of a paint chip, bought a gallon, went for it and never looked back. The dark walls make whites and colors look really clean and crisp, and it feels soothing in the way I imagine a den must feel to a little furry creature. My dog spends three-quarters of his day curled up on our bed, so he must agree.
Colors used in my room
Tips for using color successfully
Don't be afraid - go for it. It's just paint, after all - not a demolition or a wiring project or something like that. Do what you've always wanted to do, not what you think you "should."