Do button polyps change color?

[Beijo Gaem]

My BC29 has been running for 3 months now. The calcium level has been consistently measuring a low 320 ppm and the KH consistently measures 7dKH (or 125.3ppm). SG has been fluctuating between 1.023 - 1.025. Currently it's at 1.025. I've been doing 2 WCs a week, changing 5-10 L every 3-4 days. I'm running chemi-pure elite and purigen, and I've also got some chaeto in the rear chamber. My water temperature fluctuates between 78 - 81 F. I do not dose anything else at the moment, nor have I ever. (I am considering dosing calcium however.)

 

I'm running a 9 hr lighting schedule using the stock lighting. I have a couple SPS, some zoas, acans, a couple rics and a couple yumas. 2 weeks ago I purchased a small frag of brown button polyps - now they are starting to change color. They were completely brown when I purchased them and now they're starting to turn a shade of teal. Should I be worried?

 

 

Here are a couple pics of how they look now (please excuse the poor quality):

 

 

 

 

Any feedback would be greatly appreciated. Thanks fellas/ladies.

[BillyMays]

z's and p's will change colors when put in a different system with different lighting. all of mine look different then when I bought them.