A device concept for highly efficient OLEDs is introduced that allows to tune the emission color of the device over a broad range of the CIE color gamut, The approach exploits the different polarities of the positive and negative half-cycles of an alternating current driving signal to independently address two vertically stacked emission units with complementary color. Ultrathin metal electrodes fabricated by a wetting layer approach are used to achieve good electrical contact to each stack with minimal impact on optical performance.