A few other recent shots where I've used the RGB:
Just pointing up a tunnel, in white mode:
Foreground here was actually painted with a mixture of green and white:
I think I originally made this service station blue, but the pure colours from that light make it easy to tweak the colours.
This is where it's really noticeable that the beam is hotspot-free, but not diffuse: the shadows are crisp, but the lighting is nice and even.