Welcome to the forum Blondie. I don't know that much about peacocks but I do know that they turn brown as adults. As far as tree frogs go in general you'll want to get a tank that is at least 18 inches tall. It should have lots of large leaf pants with sturdy vines for them to climb in. Live plants look more natural and help with moisture retention. Most tree frogs do need good ventilation so a tank with a secure screen lid is preferred. If you're going with the peacock Google care sheets for them.