Reads your X Window System Linux screen contents and sends it to a remote raspberry that has single-color rgb lights, which are controlled using one PWM gpio pin per R, G and B. Hence it does not need splitte and grabber hardware.

This is the complete hardware setup you will need: https://dordnung.de/raspberrypi-ledstrip/

It sparsly checks a few places on the screen (250 pixels by default) and puts extra weight on those with high saturation.