In color, like in life, sometimes we try to get a little bit of everything to overcome our fear of missing out on something. The overall effect, whether in design or in life, is a lack of focus and direction, which dilutes the strength of your direction.
Don't go with rainbow **anything** unless you are selling paints or something that involves "all colors." Don't be afraid to commit, less is more. Pick a scheme and go with it based on the emotional connotations of the colors and how they work into your message. (Blue=calm, red=urgent, etc.)
A short article on color theory [en.wikipedia.org] will give you the technical aspects of what you need to do. Out of all of them, a simple complimentary scheme with effective dominants and submissives will work out much better.