If you're interested in experimenting with creating new chicken colors from existing varieties, one of the best written guides to this arcane subject is by the British poultry expert and author Grant Brereton.  At Greenfire Farms, we purchased these e-books several weeks ago and have been educated and entertained by Grant's insightful and practical approach to chicken color genetics.  He presents his material at several levels, and the new hobbyist and genetics student alike can gain valuable knowledge from a person who has created some of this century's more remarkable new varieties of chickens.  You can go here to order Making New Colours.  Highly recommended.