Is it a green tree frog or is it a whites tree frog? Maybe its just me but it almost looks a whites in the pictures. I notice a few things from the pictures so I'm not sure what exactly you asking about. I see little white spots on his back which if he is whites could be normal if hes some kind of morph or it could be some kind of infection. He looks off in colour which could be stress and what is that on his nose? If that's a open wound its severe nose rub which means he doesn't like something and is trying to get out, you can treat that with Neosporin WITHOUT pain reliever. I would put it on a couple times a day. Not sure about the colour because I'm not sure which your asking about and I'm not tree frog expert I just know the basics from being on this forum so hopefully someone else sees this. And what is the temp and humidity in the tank and what are you using to heat the enclosure.