I also had pale corals for a while, but after feeding Reef Chili and feeding more, it really improved the colour.  I was also having trouble with zoas shrinking, and that seems to be improving as well.  I've been following a thread on R2R by a fellow (Bubba) who has amazing SPS, and he advocates feeding generously. 
Yes, my cyphastrea is on the sand.  I wonder if it's a flow issue.  I have sand and so I don't have a lot of current blasting around. 
		
	
		
		
		
		
			
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