New frags color changing

[CNC_Lou]

Hey guys,
I started this new SPS dominant tank and was curious as to why the frags are going green (healthy looking green).
They were somewhat green at the base but different colors throughout when I got them and it’s been about 6 weeks.
It’s been up for about 13 months and seems well established.
Have nice coralline plus tons of micro brittle stars.
This is my second attempt as the first time it was too young and the frags either browned out or just melted.
Thanks.

 

[Kzang]

I’m not an expert at sps, but when my acros turn green my iron and/or iodine is high