Help With Deepwater Acro

[viperfish]

I purchased this Acro from J&L about four months ago. They said it was a Deepwater Acro. When I bought it, it was white with purple tips. I acclimated it properly, gave it lots of light and water flow, now it's green! I know they say corals can turn colour under different lights but this is crazy! I also heard that excessive nutrients can cause this. My params are good, my Nitrates are at 20 but that shouldn't be enough to throw anything out of whack. Can anyone shed some light on this type of coral since I am having very little luck searching online. I am running 20K lights, I don't know what J&L is running but would a change from 10K to 20K be enough to cause this?