Check out ColorSchemeDesigner.com. That site helps you by constraining your color options to complimentary colors and other appealing color combinations.
Colour is definitely a "personal" preference.....but if you go to most paint stores they have colours listed in categories like warm, cool, hot, etc. I think that the colour of a web site should have some relation to the content. If the site has a company/product logo then the colours of that logo should be used in either a similar or complimentary tone....I like blue and or green tones myself...but then again that's my personal taste :smile: