Provided is a multicolor organic light emitting apparatus having a plurality of organic light emitting devices formed on a substrate, for emitting two or more types of luminescent colors. A thickness of a layer formed between a light emitting layer and a reflection surface of a cathode is the same as that of each of first and second organic light emitting devices, and an optical distance between a light emitting surface of each of the light emitting layers and the reflection surface of the cathode is adjusted such that each thickness of the light emitting layers is varied to enhance light emitted from the light emitting layers by optical interference.