Why do some animals have bright-colored skin?

Bright-colored skin in animals can serve various purposes, including attracting mates, warding off predators, and camouflaging. For instance, bright colors in frogs, like the poison dart frog, act as a warning to potential predators that they are toxic. In contrast, male birds often display bright plumage to attract females and signal their fitness as mates. Some animals also use bright colors to blend into their environment, as seen in certain fish species that have evolved vivid colors to resemble coral or sea plants.