Hey Ryujisama, Welcome first off. Second, I would spend some more time defining the head. You've got quite a bit of poly's that are doing very little as far as defining the shape. Try focusing on the main planes of the skull and eliminate smaller faces that don't help to define the silhouette. Also included in that would…
definately some great design here..the texture may seem a bit too busy so you kinda lose the overall shape but this is definately a great portfolio piece
A tiny update on the color ranges: In the current implementation you can define a range of how many colors will be picked from the above swatch set. I also started to work on the possibility to switch between differnt swatchsets.