There already is a custom programming language for LED lights. It's called E1.31, and there are open source programs that exist to program in it (one of the most popular is called Xlights). It's what most people use to make their programable Christmas lights shows, and it also is the same protocol used in stage lighting.
If I understand correctly that’s 'Streaming ACN' e.g. more or less DMX512 over IP. In that case the image is generated on a beefy lighting desk/computer, not on the microcontroller inside the fixture (which is what this and e.g. the Lua project linked in another comment does)
WLED (firmware for ESP8266) appears to support E1.31 [1] as well as Art-Net and the WLED custom protocol referenced in the article.
