Green is superior, except you don't need the edge of green over red if you anticipate using it an night or inside buildings. Go with the red, and if you mount a red dot scope n a rifle, you can get the red or green option in one device, for oyur personal choice. I use the red holo sights except on my pistols. I even have a magentic mount red laser on my steel 1911. Of course, I do have a Veridian green laser on my Glock 23 (uses 1 lithium battery), so day or night I can shoot better off hand within twenty yards.
Short answer, red will do just fine since the vast majority of possible shooting scenarios will be night confrontations.
Those are my thoughts as well – although my primary interest is a laser sight for a rifle setup.
But the same ideas would apply – it would mainly be used for close-in scenarios.