Well, this isn't exactly a pixel art creation, but I think it's pretty darn neat. I'm working on a program that can take a base icon, and recolor it for you from a large selection of color ramps.
The single suit of armor at the top is the base image, and the program creates all the other ones from a little icon full of color ramps.
My current selection of color ramps suck, since I just had the computer generate them. There are a few on the bottom left corner that I set up that look pretty good. The program can use colors ramps of any length up to 32 steps, though that would limit how many ramps you could use to 32. With four color ramps, you get a selection of 256 ramps.
What I'd like to do is set up a pallet with a good quality selection of grouped ramps. You will be able to select sections of the pallet to use, so you could have a group of ramps for 'metals', one for 'skin tones', one for 'neons', etc. You will also be able to load your own pallet icon, if you don't like mine. ;)