D. tinctorius "azureus" is a medium-sized frog that weighs about 8 g and grows to 3.0-4.5 cm in length. Females are larger and about half a centimeter longer than males, but males have larger toes. The frog has a typical lifespan of five to seven years in the wild. Its bright blue skin, usually darker around its limbs and stomach, serves as a warning to predators. The glands of poisonous alkaloids located a defense mechanism to potential predators. These poisons paralyze and sometimes kill the predator. The black spots are unique to each frog, enabling individuals to be identified. This species of frog has a distinctive hunch-backed posture. Each foot has four toes, which each have a flattened tip with a suction cup pad used for gripping. The tips of the toes in females are round, while males have heart-shaped tips.
As with almost all frogs, tadpoles differ greatly in appearance from adults. They have a long tail, about 6 mm, with a total length around 10 mm. They lack legs and have gills instead of lungs.