An apparatus (200) for driving a display (310, 320) including an array of display elements (20), each element (20) comprising a plurality of sub-pixels of red (R), green (G), blue (B) and white (W) colors. The apparatus (200) comprising a processor (300) operable: (a) to receive input signals (RI, GI, BI) for controlling red, green and blue colors of each element (20) of the display (320); (b) to process the input signals (RI, GI, BI) to generate corresponding red, green, blue and white output drive signals for the red (R), green (G), blue (B) and white (W) sub- pixels of each element (20), said output drive signals being enhanced according to a gain factor (HS) for increasing element luminosity subject to potential color saturation occurring at one or more of the elements (20) being addressed by selectively reducing color saturation at said one or more of said elements (20); and (c) to apply said output drive signals to respective sub-pixels (R; G, B, W) for each element (20) of the display (320).