Colorful flames and smoke?
This is actually Newton’s Rings again, a colorful microscopic pattern that appeared on my sample of laser material after some isopropyl alcohol dried funny. It must have left a thin film of something behind, and that produced rainbow patterns in the same way a thin soap bubble film does. The rainbow patterns are just barely visible by eye, but under a microscope (like this), you can see all sorts of detail.
Fortunately, the fix was simple: another isopropyl alcohol rinse, followed by a more careful dry. Rainbow patterns gone - on with science!