Doing this in Linux seems like a lot more time/trouble than just putting the side of the case on (and not getting one of those silly cases with a window in it).
When I went to build a PC recently, I was disappointed to find out that the most cost effective cases that otherwise met my requirements all had those silly windows, and that some RGB components were actually cheaper than non-RGB. So I ended up with a window and RGB, despite having no desire for either!
I had to hunt around for the correct software to disable the stuff. Little did I know that this project existed at the time :)
I'm not sure what you're price range was but a lot of Fractal Design cases have solid side panels. I have their Meshify C case and the temps are great with a Noctua cooler.
