I have 2 FBTs that I bought together (they are possibly siblings-raised together). Bought from pet store couple weeks ago and when I bought them, they were the usual bright green. Now the one I believe to be male seems darker, almost a murky green. I know FBTs are semi-aquatic, but these guys are in the water literally 24/7. I thought that had something to do with it, but that wouldn't explain why only 1 toad gets darker and the other one looks about the same color. The female gets barely-noticeable darker, and then her color returns to normal after 'drying off', but the smaller one remains very dark even after drying off and staying out of the water for a while. Could I be using too much dechlorinator in the water? I probably do use a little more than suggested, but I want to make sure to get the bad stuff out of the water. He appears healthy in all other aspects. I keep their tank clean (no chemicals of course), water changed regularly, good temp, good humidity and I use a 26w UVA light off and an throughout the day and they seem to like the light. I also dust feeders with Calcivite I can't figure out why he's so dark when he didn't look like that when I bought him. Any suggestions?