An organic light emitting diode display includes pixels in which an amount of current flowing in an organic light emitting diode of each pixel is determined depending on a difference between a data voltage and a reference voltage, a control signal generator differently generating a screen brightness control signal depending on a driving mode, a register adjusting unit independently adjusting a reference voltage register value and a gamma register value at each of red (R), green (G), and blue (B) pixels depending on the screen brightness control signal, a reference voltage generator generating the reference voltage of each of the R, G, and B colors based on the reference voltage register value, and a data voltage generator generating the data voltage of each of the R, G, and B colors based on the gamma register value.