650nm has a better color gamut, but needs more mW like over 300! to balance your blues and greens. My vote is for 650nm since they emit single mode and emitters are cheap and easily field replaceable.
635nm has a good color gamut, and mw for mw is substantially brighter... BUT most emitters of show power ranges >100mW are multi mode. They will tend to shade and blur edges with red and/or kill your projection range when you defocus your other guns to match your red's divergence, that is unless you are willing to use bigger scanners and sacrifice speed for a better collimated beam.
My $0.02 worth![]()