That's way cooler than what I have. I thank you for the point of reference. With this I will definitely go back over it. If it's ok with you I may steal some bits? Either way thank you!

Here is a qick edit to illustrate what I had in mind:

Though the light source thing is not really well done, and I'm not sure if I met all your original limitations.

Those are great suggestions, thank you for commenting. I am by no means a professional so I'm surprised at how tame the responses have been lol. 

The clusters seem totally random as if it were automatically color reduced, I suggest working them over with a clear lightsource and concept in mind. The darkest color is really underused as well.

Super cool to see how proper design makes the character seem distinct. It is a bit noisy though.

This is super cool, I get a great sense of the 3-dimensionality of the character!