Can change colors from solid green to mottled grey/green to better blend into their surroundings
Interesting fact:
There are two species of gray treefrog in eastern Kansas, Cope's (Hyla chrysoscelis) and Eastern (Hyla versicolor). They are indistinguishable except for the number of chromosomes. H. chrysoscelis are diploid (have 2 copies of each chromosome) and H. versicolor are tetraploid (have 4 copies of each chromosome).