You can accomplish what you want with 1 rgb light but you will need multiple controllers, one for each function (color) you want to use, BUT beware that the way those rgb lights work is yellow light is created by using blue and green led's. So if the light is in front of the person it wont "look" yellow but the illumination from it will be yellow even though the customer will see green and blue dots.
So we use red, green, blue, and multi color, which is all three rgb led lights togther. but that actually illuminates white in the bay. We added a second led g&g light that was solid yellow for our hot wax function because we didnt like the look of the green and blue led's creating the yellow look based on where the light was positioned
If you want the schematic i drew up when i designed ours i can send it to you. Its rough but informative. I even had tss and meanwell (the ac/dc converter company) check the schematics before building it.
All you do is take the signal from the digital output cards (in the
pdq g5 case anyway) and run them to ice cube relays in another electrical box. You need 1 relay for each function you plan on using. You will need a special 3 way relay for triple foam rgb color, single colors use single pole relays.
Ice cube relays do have problems with led light clusters, they eventually fail. Not sure if there is a beter relay out there yet for led lights. I used what was available to me at the time. I was told it is a "known" industry problem with them.
Besides the relays, the extra junction box also contains the ac/dc converter and 1 controller for each function. So in our case i have 5 relays, 5 controllers, and 1 converter plus all the wiring. The tricky part was wiring the controllers properly to prevent cross over electrical signals.
There are photos of our setup at the link to the old thread i posted above.