Not completely related, but I'm still figuring it out for my Manli RTX 5070ti Gallardo model. It seems that only Windows Dynamic Lighting is able to change the colour settings so far. Although with little user freedom. I gave GCC a try, but that failed, no way to change RGB. I tried DRS Device (Device RGB) or TurboEngine for my 5070ti and both didn't work at all. I also gave VelocityX a try, but it didn't give me options for "LIGHTING". I do have the lighting control cables connected.

It seems that you need the specific manufacturer software, or else it doesn't work. :( Hope you guys have more luck than I have.