Adobe offers a free online tool to create color themes for your work.
Adobe Kuler "is a web-hosted application for generating color themes...Whether creating websites, interior designs, scrapbooks, fabric patterns, graphic identities, or any other visual, you can experiment quickly with color variations and browse thousands of themes from the Kuler community. Designed both to stand alone and to complement Adobe Creative Suite® software, Kuler uses Adobe Flash® technology to bring you online tools for color theme creation."
You can use it by applying standard rules of color theory or experiment on your own. The themes you create can be saved and shared. Check it out.