Damn this is cool. It's kinda amazing that it is all done in a few hundred lines of code. I see there is a skinColor method and setting defined as

    skinColor: [0.78, 0.57, 0.44]

I was curious how it worked with darker skin (I admittedly don't understand what the numbers mean without further analysis), and It came out pretty well (it may default on lighter skin, i don't know)

http://imgur.com/a/CKUIo

images found on google