Describing Hair Colors
Here’s some places to go if you’re tired of using the words ‘brown’, ‘black’, ‘blonde’, ‘redhead’, etc. Also good places to get a more definite idea beyond the generic and get a better feel for your character!
List of Hair Colors (ObsidianBookshelf)
Human Hair Color (Wikipedia) ~ With extra links
(Above source: http://www.latest-hairstyles.com)
BONUS!: Describing A Person - Adding Details (covers hair, skin, face shape, etc)