Lehmann's frog males and females reach 31 to 36 mm in length. Its skin is smooth and the first digit is a little shorter than the second. Three color morphs exist. Red, orange, and yellow against dark brown or black background. Most of the frog is dark but it is encircled by two brightly colored bands; one behind the head and the other around the hump of the back. This pattern continues on the belly. Each individual displays different patterns. Arms and legs also have colored bands. The toes in males are silver at the tips.

This bright color pattern is known as an aposematic coloration and warns against predators. Oophaga lehmanni is poisonous in the wild but in captivity it does not consume the food it needs to become toxic. This species is most similar to Oophaga histrionicus but lacks the histrionicotoxins which are present in O. histrionicus (Walls 1994).
 
Named for the late Federico Carlos Lehmann Valencia, a Colombian conservation biologist and ornithologist. Founder of Museo de Ciencias Naturales in Santa Teresita de Cali, Colombia in 1963 (F. Carlos Lehmann Valencia website 2001; Dendrobatidae Nederland website). In 2011, the genus Dendrobates was subdivided into seven genera, including the new genus Oophaga by Brown et al (2011).