This artist is clearly dealing with colour, although I don’t think he’s only sorting by colour. When I tried to go to his actual site (not the blog this came from) nothing happened so I couldn’t investigate further. It looks like he’s using size as well. I thought it was funny and an interesting way to look at things. I imagine that wherever he looks things start automatically rearranging, like in Inception lol.
Click on the photo to see more.