Ginger

I think you've done pretty well with the colours, myself. My only real critique of the shading would be the dark side of the nose; I feel the hard dark edge throws the angle off ever so slightly, and may have required more feathering out to achieve the effect. That said, your facial proportion does go slightly awry at the forehead area; the eyes should be more of a centre point on the face, so it seems like the forehead and the rest of the top of the head needs to be proportioned better to the lower half of the face below the eyes.
These are all very minimal details in the face (no pun intended) of the entire piece, however; this shows incredible skill at digital painting, and after a few more of these, I think you'll find that it comes easier and easier, so keep at it!