Some people will say that rainbows shouldn't be mixed as they can cross breed.
I personally have red rainbows and they are really happy with my blue rainbows and my parkinsons rainbows. Parks. are good if you need something swimming higher in the tank as they like the top quater where as reds swim round the middle and anywhere else they feel like. I have seen them in other tanks with different rainbows like bosemans. Don't know about neons as don't have them myself
