10 colors? For this piece you could have easily gone with as little as 6 colors.
There are shades of color that are either unnoticeable or could have been done with an already existing shade. There's also some inconsistensy in your ligthing. The shade on the hat is rather dark, whereas it's very light on the face, it's an odd contrast if you assume that both the face and hat have the same lightsource.
I also find the color sceme to be rather dull. You had 10 colors to use, so why not utilize them with a bit more imagination?
I'm also finding the shading on the neck kinda wierd.