I have a friend who can see neither green nor red - being "red green colour blind". He uses a Trijicon orange I think.
I have no experience with Holosun, but my (admittedly few) dots and illuminated scopes are red. I've never had a dot wash out in bright light as they are self adjusting (brighter in he day and less intense in the dark), but one does get a bit of "dot flare" at times at the highest settings and that is also a function of the quality of the dot and the light. Most of the action shooters shoot red. I think the risk of green is losing the dot against foliage on a transition between targets with trees or a grassed backstop, so I would prefer red. Indoor ranges probably make it a moot point.