Here are some guidelines summarized by the EWU Multimedia Commons (MMC). To use and get one-on-one help with design software such as Photoshop, Illustrator, and iMovie, visit the MMC in the JFK Learning Commons!
Colors across from each other on the color wheel (called complementary colors) often pair well together. So do colors right next to each other (analagous colors).
Image credit: http://www.great-houses-scotland.co.uk/how-to-choose-a-colour-scheme/