The Brown Tree Frog (Orchestra ver.)

I saw a rain frog for the first time in a while on a mountain road during the rainy season.
It was a small brown tree frog.
There were similar frogs around it.
Compared to the brown frog, its shape and size were almost the same, but the surrounding frogs were green or yellow-green.

Which is correct: the person who calls tree frogs green or the person who calls them brown?
When I asked my biology teacher, both answers were correct.

Tree frogs can change color depending on their surroundings. If you place it on top of a fluorescent pink color, it will turn into a fluorescent pink color.

However, it seems that some tree frogs are unable to change color or are slow to change color.

A student who doesn't like being in a noisy classroom, so he spends his breaks alone in an empty spot in the back of the library or behind the gymnasium.
These children overlapped with a brown frog that I saw during the rainy season and was not good at matching colors.