I got all my Whites tree frogs at Petco as long as they are healthy looking and being housed correctly go for it. My latest two, Skitter was green in the store and Olive was dark brown. Now a month later they are still the same colors, however Olive is starting to turn green a little more each day. The only time I've seen Skitter turn brown is when she's very stressed over something. My older frog Shrek, turns brown when she wakes up but lately has been a pretty green while she sleeps.