Pacific Tree Frog

Notes:

Green and brown color morphs One of the most interesting features of these frogs is their ability to change color from brown to green. Previously, it was thought that there were two different fixed colors that an adult tree frog could be. Now it has been found that some of them are able to change between the two. They can also change from lighter to darker, shift from patterned markings to pure colors and vice versa, and even display combinations of colors, brown/green being the most frequent. (en.wikipedia.org)