My suggestion is you have a way of seeing the special hair dyes on your character before you purchase them. I think this would be ultimately useful and most likely sell more hair dyes.

Also I would love to see:
More facial options such as noses, facial shapes, hairdos
More facial accessory options such as tattoos, piercings, glasses
and heres the big one
Special attack animations !!!! People love seeing characters do new things and animation is expensive. I believe this would sell extremely well.