You don’t have to bother and just buy a tape with RGB lighting and stick it in the right places. But of course, if you want everything to look good, you can buy fans with backlighting or a compartment cover with controlled backlighting.
This is literally true. I bought many different computers, different cases. But when I started setting up my team from scratch, I realized that it was better for me to assemble what I wanted myself, especially the lighting, I literally did it by hand.