A driving system for an electro-luminescence display device includes an organic light emitting diode (OLED) panel having a plurality of pixels. The pixels include a red pixel, a green pixel and a blue pixel. The driving system includes a controller and a level shift unit. The controller receives a first digital data and converts the first digital data into a second digital data for a gray scale display. The level shift unit converts the second digital signal to a data voltage and supplies the data voltage to the pixels. The level shift unit operates to provide a different source voltage to the red pixel, the green pixel and the blue pixel. The red, green and blue pixels may be independently and separately controlled.