Organic light-emitting diodes (OLEDs) using polymer blends as a single emissive layer often suffer from large color shifts with changing operational voltage. Until now, such devices cannot stand the critical demands of lighting industry. In this contribution, we introduce a pulse-width-modulation-based driver concept, enabling the user to simultaneously and independently adjust color and luminance of a single device with two contacts. This concept makes color-shifting OLEDs highly interesting for ``mood-light'' applications.