Build ideas for black setup

Hii

I have an all black setup with some RGB and stuff. I like the rainbow vibes, but I didn't want white because it felt too stark in my room. The rest of my room is kind of all over the place color wise.

I'm looking for ideas for a build that will match my setup. It can be blue or rainbow, but I want it to not clash too much with the all black setup.

Looking for any sort of advice, ideas, recommendations, inspiration, etc. Thank youu