Colour Theory
http://dev.opera.com/articles/view/8-colour-theory/

Goin, Linda
Opera
2008

Abstract:

In this article, I’ll cover colour basics and three simple colour schemes so that you can feel confident about choosing colours for your site. I’ll follow up this article with another piece on how to simplify these colour choices. After all, it’s more fun to enjoy the compliments on your Web site design than it is to sweat over the colour choices.