Systems and methods providing driving voltages to an RGBW display panel. A representative system comprises a data driver with a reference voltage generation circuit that is operative to provide reference voltages according to a white component signal (W) extracted from three color input signals (R,G,B), and a digital-to-analog (D/A) conversion unit that is operative to generate driving voltages according to the reference voltages, the three color input signals and the white component signal.