yep proportions...
proportions is practice x 10000000
but you already got something decent
keep goin you are on the right track, as for the colors...nothing to say except that it rock
my favorite part is the face, you were able to draw a fine yet stoic expression
added to fav
also dont worry about the hands, hands are pain in the ass and take years to get right...i always screw my hands myself so dont worry about it