Here's my eighteenth illustration for Drawgust, a polluted stream!
Originally I wanted to have the two pipes spewing out different colors, and then have them mix as they flowed downstream, but as I drew, I felt like I didn't have enough differentiation in my colors (even when mixing) to have that look right. And I just didn't feel like doing it.
Still, I like the way this turned out. The garish colors make it look like an album cover or something.