The LEDs are emitting that pure color at very high saturation levels. So you’re seeing clipping there, where the color falls off only as the light output is driven beyond the camera’s ability to capture it.
Find yourself a couple C-stands and a good sized piece of black fabric. Duvetyne is nice, velour works well too, from my direct experience.
Cut a small hole in the middle of the black fabric and use that to put the lens through while standing behind it. The reflections in the glass will be of the black cloth.
With how you’d described it, I’d look to bounce the largest instrument I had off the ceiling for a nice even wash. Mirror/vanity practicals would certainly add to the look, maybe they could be lamped down some?
Before getting any deeper, though, what’s the mood/nature of the scene?