"My how colorful," is the first thing my wife and I want people to say or think when they enter our house. In our Las Vegas house we decorated the main floor in the colors of Mickey Mouse and the second floor in the colors of Winnie the Pooh (and Doctor Suess for the tike). In our Orlando house we've shifted our pallate a bit, we have less canvas to work on, but the color effect is still there.
We didn't do this just to be bold in our design, although that's part of it, we did it because color affects one's mood. We've known this for years, but only recently has it started to seep its way into interior design.
The NY Times has an article on some designers who 'design happiness' through colors. Check out the great slide show for examples of how you might impliment a little (or a lot) color into your next remodel.