I think this would probably work better as B&W or at least desaturated more than this. The yellow is very strong.
My suggestion is three-fold. First, cut down on the amount of writing on the render's face. Never want heavy stocks like that over a face. Second, get some stronger lighting on his face, primarily on the right side (our right) since that's where the light source of the sig is. Third, make the entire thing B&W with some nice contrast. Just remember that contrast is key with B&W, don't be afraid of it.