We demonstrated an efficient color-tunable electrophosphorescent device fabricated by a photo-bleaching method. Electroluminescence studies indicate that excellent device performance can be achieved through efficient Forster energy transfer from the conjugated polymer to the iridium complexes by improving their miscibility. The use of a very low concentration of red phosphorescent dye and the easy degradation characteristics of conjugated structure of the red dopant enable color-tuning from red to green emission by a simple UV-irradiation process without a sacrifice of luminescent properties.tp (C) 2011 Elsevier B.V. All rights reserved.