When I bought my FBTs, they were a bright green with a bright orange underbelly.
As they got settled into their tank, they went from bright green to a dull green/brown.
Whenever i disturb them with a water change, they go back to bright green for a day until they settle down again, then back to brown.
So my question is, do we think something is odd with the tank, like something off with the water and they go to brown? Only to be green when the water is fresh? Or is brown their natural color and they only go green when stressed?
I ask this because i have read limestone can cause an abnormal PH level in tanks which could cause stress. I have no idea if I have limestone though, i would have no idea what it looks like.