While this article from Science Magazine is technically discussing whether a species of earthworm should actually be broken up into different species (possibly up to five!), I couldn’t help but admire just how pretty the worms in this article are. In the image accompanying this article, you can see two different worms displaying a rainbow of colors on their bodies. What I’m assuming is dirt being digested adds to the different shades of the worms.
(Unfortunately the video at the bottom of the page doesn’t give very colorful images of the worms; just a lot of beetles attacking the earthworms. If you can find other ones, post them in the comments).