For the "goats" theme, Spoonflower gave us the colors to use:
Color by COLOURlovers
I definitely wanted to feature the eyes of the goats, as that's one of the most distinctive things about that type of animal. So I went with a straightforward arrangement of simplified goat heads.
This didn't quite make it into the top half of entries. My favorite was this one, which used crosshatching to expand the apparent range of colors, for a lovely glowy look.