Green splatter hammer losing its green color?

[tnewell]

I have owned euphyllia for quite some time now, and haven’t had anything like this happen before. My 4 heads branching splatter hammer seems to be losing its color and almost turning see throughish purple. I know this can be due to high lighting and what not but let’s take a trip back 2-3 months with this coral. I had a blond moment and dumped freshwater into my tank(I thought it was salt). That called for me pulling my corals out immediately as the salinity dropped drastically, and me scrambling around town at 8pm looking for extra salt to mix. After the corals were pulled out and sitting in a tubaware for 4 hours in colder water(I was dumb and didn’t put a heater, also no water movement) and they BLEACHED. All my corals had a nice recovery except a brain coral which is on its way to 100% atm. So anyways what I’m trying to say is that it’s been healed for a month or so and adjusted to my flow, and it’s only been raised half an inch from where it was. So if this is zooxanthelle dying off, how do I prevent a full loss of color?
i feed every 2 days with reef roids and he eats like a pig. He is growing new branches with green on them, so that leads me to suspect that the green on these branches have gone through to much stress.
my tank params are
Ph-8.1
Nitrite-0
Nitrate -.25(everything is used to it)
Phosphate-0
Salinity 1.025
Alk and calcium I’m not sure of, I’m waiting for Christmas to come around to buy testers. I do weekly water changes though.

I will include pictures of the coral when I first bought it, then pictures of it now. The first picture is a week after I bought it, second pic is after the massive salinity drop, and last is the hammer now.
Any ideas on why it would loose some of its color?

 

[ReeferWarrant]

I don't think too much light would cause less fluorescing and actually the contrary. Too little light causes most SPS to go brown in color to create more energy. I just read an article about the use of the fluorescence and they speculate that it is the reflection of harmful lights to the coral. I'd wonder if the purple is the zooxanthellae and the neon green is the means of restricting harmful lights.

Why Do Corals Glow in the Dark?

A new study suggests they use fluorescence for photosynthesis.

www.theatlantic.com

Regardless, I'm curious to hear other input on this. I have not seen this either and have a handful of Hammers and Frogspawn.

 

[DangerDave]

I have a branching splatter hammer that looks identical to yours. As it’s grown and split over the last few years I get different colors on the new heads. Some all green/yellow, some all blue, and everything in between....

 

[tnewell]

I have a branching splatter hammer that looks identical to yours. As it’s grown and split over the last few years I get different colors on the new heads. Some all green/yellow, some all blue, and everything in between....

Yeah all the new branches are different color, but primarily purple. I see the green speckled slowly turning back to purple. And as the green slowly fades, the purple turns to a more see through purple. Which leads me to believe reeferwarrant