So I work at a pet store and over the months there I had been eyeing up one of the Whites Tree Frogs we had, I finally decided to take him home with me and he has now been with me for two days.

His enclosure temps and humidity are all good and he was eating perfectly fine when I fed him at the pet store two days ago (I haven't feed him since because I wanted to give him time to settle). Tonight when I looked at him I noticed a neon green spot on his head so I naturally decided to google what it could be and got so many varying answers that it's impossible to actually discern what the spot could be, some info I got said they could be caused by stress or dehydration, other info implored me to seek out veterinary help immediately or my frog would die.

So I've decided to come here and get some opinions from experts, what do you guys think they could be? I really wan't to be optimistic and just chalk it up to him being stressed because of being in a new environment. Also something else to note, instead of sleeping on the glass like he did in the petstore he instead opted to sleep under the moss in his tank, could they be related?

Any advice at all would be greatly appreciated, thanks!