FI agree with the advice to feed heavily/keep a large fish load. Soem of the most healthy SPS tanks I have seen have been kept this way, contrary to the "low nutrient" method. Joe Burger (
www.cnidarianreef.com) had an AMAZING tank, and I think a lot of the reason was that he was culturing phyto and rotifers and feeding heavily. When he broke down his tank this year some of his corals were so large they had to be donated to the aquarium.
All of which has nothing to do with color though--
My first question, especially pertaining to SPS is wht do you consider good color? Most people would say the fancy bright blue/pink/purple colors, rather than the boring brown. The boring brown colors are from large quatities of active zooxanthellae in the tissue, and these corals will probably grow faster given good food/light. in contrast, many of the pigments that are so pretty are there as UV protectors: the coral produces them in response to "bright" light to protect the tissues (at the expense of growth--limited supply of energy will go towards growth or UV pigment production, but not both well). This is not to say that the bright specimens will not grow, just that they will probably grow more slowly. When people grow corals for sale, they often keep them under low K bulbs for the bulk of their life, where they grow brown, but rapidly, then a few weeks before sale they put them under high-K bulbs to "color up".
What does this mean in terms of husbandry to produce color? I would tend to think higher K bulbs, and lots of them (this is why you see better color with MH), and feeding to make up for the decrease in photosynthetic activity.
Christine