I used my hydor light. I took it off my decoration and out it in the cave. They love it and it makes my ceiling look like a fish tank at night. You see the green on the ceiling and the fish swimming infront. I've had it for over a year and the light is still perfect. I dno bout a color changer. I think it becomes to tacky. My theme is to make it as real as I can in the tank so if I get a light green makes it have a really nice glow inside