Every time I buy a green-colored SPS coral, the color changes within a few weeks. Either it fades to a yellow-ish pastel color, or else it turns blue! I don't seem to have this problem with pinks, purples, or blues. Just green. My lights are 4x54W Tek fixture (1xfiji purple, 2x blue plus, 1xUVL actinic white), 2x48" Reefbrite LED strips (1 blue, 1 white) - for a 90g tank. Flow is 2xMP40 ES, 1xK4, return pump. I vodka dose and dose MB7, and dose amino acids. recently I also started dosing iron and potassium supplements to see if they could improve my coloration - for about 1 month - so far no change.