GMMK Pro lighting issue

Welcome b4rry!

Most users apply their lighting profiles to different layers on the keyboard. You then just switch layers to get the lighting you want. So for your hot keys, you just want to change to a different layer(aka not try to change the led’s themselves).

Personally, I do something very similar, but I use the fn+hotkey to switch between layer 0,1,2, & 3.

As a Linux user I would also suggest taking a look at QMK. I prefer QMK for better macro support.