That's pretty neat; some of output are beautiful!

Mine is also pixel coloring at the lowest level. I have a shading kernel in GPU doing the low level work, mainly applying colors recursively like fractal. I got sick of writing shader code so I make a high level language supporting math operations in concise expression that are compiled to shader code in GPU. The main thing is it supports functions. That let me reuse code and build up abstractions. E.g once I get the "ring" pattern settled, it's defined as a function and I can use it in other places, combine with other functions, and have it be called by other functions.

One of these days when I get some time, I'll formalize it and publish it.