I keep mine under a single 250w MH 12k Reeflux bulb with T5's and LED's. It is directly under the lights but I keep it lower in the tank. I have the turquoise polyps and I am getting a green base which I wondered about so I am glad to hear that is kind of normal. The polyps were brownish for quite a while but as it has grown and my params have settled into a good groove they turned a beautiful turquoise? My picture doesn't really show the hot pink I am getting but it is very bright.
Here's mine. It's not getting great reds probably not getting enough direct light. It's off to the side near a brace in the tank.
I've got it under AI Hydra 52's. I will be bumping up my whites to around 75% to see if that helps