Since I've only had these guys a short time, am really not sure what is normal...glad to know that their slowing down is probably normal. Do you provide a heat source for yours? I am using a 60 watt red nightlight (reptile bulb) during the day, and turn it off at night. I hate to admit this, because a lot of people may frown ~ but these guys originated from our lake, and we took them home with us (I let my kids convince me I was saving them from certain death from predators!). Both were brilliant green, one turned "gray" with dark toad markings within a couple of days, and the other had maintained his color until this week, and has now suddenly changed gray as well, no dark markings though. Is there anything I can do to encourage the green coloring to return? I have green paper under their aquarium and on the back side of it and some fake green plants inside. Do you know of anything else I could try? Was thinking of getting some of that reptile carpet that is very green. They spend most of the day hiding under a hollowed out tree log.