Most of them are black and either green or light blue, with the black in bands or spots. The Hawaiian frogs are metallic green or brownish-black. The adults are approximately 4 cm long. As is true of most frogs, adults have a fused head and trunk with no tail. Tadpoles use gills to breathe, unlike the adults, which breathe through lungs.
Tadpoles also lack legs and have tails, which is appropriate for their watery habitat.
Another extremely important physical characteristic of D. auratus is the poison glands located throughout the surface of their body. Their bright colors are believed to encourage predators with color vision to avoid the frogs. The boldly contrasting patterns may be aposematic to those predators that lack color vision, although this has not been proven. Approximately 90 alkaloids have been identified from all the species of dendrobatids. They capture their prey by using their sticky, retractible tounges as well as their excellent eyesight.