I got a 8in wide piece about 2 months ago identified as Acan echinata. Nice pretty bright orange with purple center and some splashes of gray/green. I have it 18in away from a 216 watt T5 lights. It has grown a polyp or two since I have had it, but now I notice that the orange is just getting a little faded. What can I do differently to try to enhance this orange color?