as long as it is still eating and acting normally. treefrogs change color for many reasons: temperature, camoflauge, humidity (could be too humid or too dry), diet (could be hungry or eaten too much), seasonal, time of day...
there are a million reasons why treefrogs change color, many of which are not evident to the keeper. my whites are beautiful during the day but turn a bruisy color at night, who knows why.

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A room of herps.
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