The present disclosure relates to an organic light emitting device (100), including: a substrate (110) defining a first pixel region (SP1) and a second pixel region (SP2); and an organic light emitting diode (D) disposed over the substrate (110), wherein the organic light emitting diode (D) includes a transmissive electrode (230), a reflective electrode (210) facing the transmissive electrode and an emissive layer (220) disposed between the transmissive electrode (230) and the reflective electrode (210), wherein the organic light emitting diode (D) respectively corresponds to each of the first pixel region (SP1) and the second pixel region (SP2), wherein the emissive layer comprises a first emissive layer (220-B1, 220-B2) and a second emissive layer (220-G1, 220-G2), wherein the first emissive layer (220-B1, 220-B2) of the organic light emitting diode (D1-B, D2-B) is disposed in the first pixel region (SP1) and includes a first blue emitting material layer (350) including a first blue fluorescent compound (352), and a second blue emitting material layer (360, 460) disposed between the first blue emitting material layer (350) and the transmissive electrode (230) and including a second blue fluorescent compound (362, 462) and a blue phosphorescent compound (364, 464), and wherein the second emissive layer (220-G1, 220-G2) of the organic light emitting diode (D1-G, D2-G) is disposed in the second pixel region (SP2) and includes a first green emitting material layer (550) including a first green delayed fluorescent compound (552), and a second green emitting material layer (560, 660) disposed between the first green emitting material layer (550) and the transmissive layer (230) and including a second green delayed fluorescent compound (562, 662).