White light with good color properties color rendering index=82–87 is generated in a simple organic light-emitting diode comprising an emissive layer, composed of an undoped tris 4-methyl-8-quinolinato aluminum Almq3 sublayer and region doped with an orange-red phosphorescent dopant, bis 2-phenyl-1-quinoline iridium acetylacetonate Ir pq 2acac . Electron-hole recombination in a thin spacing Almq3 layer results in blue-green fluorescence, while the formed triplet excitons diffuse to the doped region and are harvested by the dopant to emit orange-red phosphorescence. The combination of blue-green and orange lights results in warm white light. This approach takes advantage of efficient migration of triplet excitons while being less demanding in terms of fabrication and color matching.