You see, this is the problem, or challenge, with SPS. You can do everything right, and exactly what someone else does, and just not get the expected results. My current incarnation of SPS tank is pretty much the same as every other tank I've had, however this time my colors are awesome. My growth is, however, nowhere near what I've had for my previous 8 years. Go figure.
Essentially you need to tweak and twist until you get it right. Then, next month when things start browning up again, you need to figure out exactly what you tweaked last month
Yes, frustrating sometimes, but when you get it right, it's all worth it.
Basically, IMO, it's all about nutrients. Nutrients make corals brown. Whether it's NO3, PO4, TDO, etc, who knows. It's different for each tank. Make sure you clean your skimmer twice a week. If it doesn't need it, it might not be enough skimmer. Use good carbon, change it once a month. Do you use a phosban reactor? If not, start. Review your feeding regime. Too much food can be detrimental. Use filter socks, keep them clean. It's all about clean. Too much crap in the DSB? Maybe time to remove sand.
These are all the tweaks I've done this time around, and it's working for me. Lighting isn't important, it's what you like to look at. More PAR can give you more growth, but don't worry about growth, it will come. People have been chasing colored SPS with K ratings for years, it's not the secret ingredient. Worry more about flow, it's all too often overlooked.
And clean. Keep all your export mechanisms clean. And pray to the reef gods, it can't hurt!