Thanks to everyone who helped with this! This was my final design.
I chose the black because of the printer I was going to use - and the suggestions led me to combine 2/3 with more dark areas behind the head. It looked awesome in person! I was very happy.
If anyone wants one of these, I might be able to sell them to people in the US/Canada - 18x24 (large, not quite full poster size but very big) for $30 plus shipping. Normally they are 35 just to print at Kinko's, but I get a student discount.
If you want one, please send me a note for now.