1. A method of controlling an OLED display to achieve desired color points and brightness levels in an array of pixels in which each pixel includes at least three sub-pixels having different colors and at least one white sub-pixel, said method comprising selecting a plurality of reference points in a pixel content domain with known color points and brightness levels, identifying all possible tri-color sets of three sub-pixels from the at least three sub-pixels having different colors and the at least one white sub-pixel; for each tri-color set of three sub-pixels, determining a share of each sub-pixel to produce the color point and brightness level of each selected reference point, and selecting the maximum share determined for each sub-pixel as the peak brightness needed for that sub-pixel.