Looks kinda like a Candycane to me
it needs to re establish zooxanthalea algae....if it makes it, and has proper conditions, the color can come back...blue to green is healthy in the common type!
You are a think tank. I would move them to the top. I have had luck with PC's with candy cane, but no more than six inches in depth (I had a 96 watt 2 10,000k and 2 blue actinics on a four pin) Even then, it was tricky for me to grow them....when I was changing water every week, they did the best!