Red gels, green and blue paint, studio flash-heads.
The setup was fairly straightforward, though the shininess of the wet paint was actually quite difficult to photograph without throwing too many harsh highlights:
snooted flash from 10 o'clock for "rim"
big shoot-through umbrella around 2 o'clock for "fill"
red-gelled flash pointing backwards to a white foam-core sheet for the background
wires, radio triggers and optical slaves for syncing the flashes to the camera
