Damnj, a LOT of talented deviants didn't get in the tribute book. I'm kinda glad that I didn't apply, as I wound've had no chance against a lot of the grogeous artwork. The colors on this is well done, though the colors are a bit muted.
I think something to consider is that when colors get lighter, they don't just get whiter. They get more of a different color. Depending on the light, red will become more orange and yellow when it's hit by light, and become more purple and blue in the shadows. Maybe what this piece needs is a bit more dynamism in the color choices.
The reason I say that is because as far as proportion and style and composition, this is a nice piece. And the coloring is good, and I can tell you worked on it very hard, I just think that extra boost would come from color choice, because you've got value down no question.