Its a pretty damn good start, though there are some things I would like to see you improve on.

-Line quality: your lines look really rough around the edges, you need to clean those up and make them a lot smother.
-Color Choice: The colors you're using aren't really that attractive, I'd like to see you use some colors that contrast better with each other in the future.
-Shading: Spend some time on google and youtube looking up little tutorials on shading and see what you can take away from it to improve yourself.

Overall you're a lot more creative with your first head than most people are, so I'll give you an A for effort there. Can't wait to see what you do for your next head man.

P.S. Pure, Void, Elf, Platinum, Azurite, Acid, Cobra. These are some good colors that a lot of people like.