Well I dont think I am that good and in a middle of a picture for coloring so I need some advice.
[IMG]http://i7.photobucket.com/albums/y289/VeniVeniVoom/sethhalfwaydone.jpg[/IMG]
Seems like the skin tones need more contrast or variance. Its a little too...undefined when you use the same colors. But I like the shirt colors. Leave that. :D Maybe add some light blue somewhere into the picture to get a good overall balance. The hairs a bit plain, but hey your not done yet!
I think the skin looks great. You've got the kind of style that I really adore, it's mellow and doesn't rely on lines. It actually reminds me a bit of makani.
I can't think of much in the way of advice at the moment. Maybe darken the shadowy area under the chin, define the mouth a bit more? Also, the right nostril should be higher up, or his nose will be lopsided from the front. P: