Symbiotic algae play a roll in the color of the Anthozoa (soft, lps, sps, corallimorpharians, colonial anemones [zoanthids/palys], true anemones) and can be alterd to an extent with the play of lighting by moving closer to or away from, but I think this would only increase or decrease the shade, ie; lighter vs darker as zooxanthellae are brown to golden/yellow and increase in number or decrease. What give the individual Anthozoa fluorescence is the pigmentaion within which has been marked as just four autofluorescent pigments. These four pigments fluoresced with peak wavelengths near 486, 515, 575, and 685. Maybe the use of lighting that focused more on one or two wavelengths would increase the pigments to higher elevations if used over extended periods and bring about color morphs, which is probably what already happens to a certain degree within the closed system as we have noticed many times with zoas color morphing. Trying different bulb types would probably be sufficiant to bring about these changes over a months time. Just an idea. Not really sure the effects of running in the lower color spectrum range exlusively and the effects of chlorophyll though.