My green tree frog has suddenly lost her bright green color and has turned a dull greyish-green. Normally her coloring fluctuates throughout the day, but she hasn't changed color or moved (as far as I can tell) at all for 4days. She is definitely a mature frog. I caugh her in my yard this past summer, so I really don't know her age. Could she be old? She is in a large terrarium with other green tree frogs, and none of them are displaying similar symptoms.