Moonlights are benificial only for the owners. They will help lure out your nocturnal fish. I have tried several different styles, and colors, and the best I have found is the blue R2 moonlight. Dependent on the fish however. I noticed most of my cats reacted well to the blue color, but knives respond better to the green. By the way, Silver aros look awesome under a blue light.
i've always heard that fish react to blue light the best and red lights cant be seen by them. Something about them reacting to blue light more because water reflects blue light and the opposite for red.