An OLED display device includes an array of light emitting pixels, each
pixel having three or more OLEDs for emitting different colors of light
specifying a gamut and at least one additional OLED for emitting a color
of light within the gamut, wherein the power efficiency of the additional
OLED is higher than the luminance efficiency of at least one of the three
or more OLEDs; and means for driving the OLEDs in the pixels to produce a
given color and luminance at a reduced power usage.