We have a few multi-channel drivers around, some specifically made for RGBW lights, so the channels are operated separately from each other. Here’s a thread Texas_Ace started to work on a 4-channel driver for a RGBA Light Saber. ToyKeeper was going to write firmware for it. I don’t know how close any of that is to completion. tterev3 was selling his MELD-X drivers here, but deprecated the thread because of lack of interest. You should still be able to get some help from him if you PM him. The driver boards and even some interesting multi-emitter PCBs he made are available on OSH Park, but you’d have to get the firmware-flashed MCU from him. DRJones also made a RGBW driver, I thought. I don’t know how to contact him now, and I can’t find a link, except this old thread strangely asking for something very similar to what you’re looking for. Hmmm…
EDIT: Oh yeah, forgot to say, the tterev3 MELD-X driver already has support for UV as well.