I maked an edit, perhaps more for my benefit than yours. Didn't add any colours, gave the viewer more something to look at and a bit more of a story is told. The angle I was going for was street-thug that does his business on a skateboard. Though I highly doubt I got that idea across at first glance, the idea is at least recognisable sooo you know what the heck I'm talking about.
I aimed for a bit of "every colour everywhere"... as best I could understand the concept, to evade the current "THIS PART IS BLUE. THIS PART IS BROWN." aspect that's going on at the moment. I added more or less random belt buckles on his backpack straps, because buckles always look cool, and they help define the straps for what they are, as well as provide an insight into function. I gave him a gun right next to the most visual-weighty part of him (his left thigh, with the chain and all) and though it might be small, it's evidently a weapon of some kind, which is all I was going for.
I also lowered his zipper just to see if it would make a positive difference, and I'm not sure it did.
He also has rougher knuckles on his left hand, scratches on his skateboard (the idea is that he notched it to represent successful hits, though have it ambiguous to represent scratches if the need be) and a hole in his knee. If I had the pixel finesse, I'd attempt to make is pants look like cloth, and his shirt look like cloth. I tried, evidence of which can be seen in the more-or-less random pixel placement. The smooth shading is appealing and calming, but that's not exactly what I'd be going for, were it my piece.
I still think the final result is great, but I also think it could be pushed to a more interesting and appealing design. Hopefully I didn't crush any of your views in my edit, and hopefully it gives you a clearer notion of what I mean by character
Cheers!
(P.S. I did no intentional changing of the palette :O! That must have come from... random extension changing.)