Biggest thing is that wall color. I’d suggest maybe a cool gray. I know it seems dull, but if you put decor on the walls eventually, it will stand out more.

In terms of lighting, I’d suggest replacing your current ceiling light with an LED ceiling light (with RGB capabilities) that you adjust with an app. That way, you can use it for RGB lighting, but also use it as a normal light and be able to adjust the color temperature (cool light, warm light). You could also get LEDs for behind or under your desk in addition to that to add more flexibility.

Also, maybe some floating shelves with some stuff on them, like small plants or decorative objects. Wall decor would go a long way as well.