apparatus for color correcting a display module is disclosed . the display module includes a plurality of light emitting elements such as leds . the leds typically include sources of nominally red , green and blue colors . the apparatus includes a device for activating a light emitting element to emit an uncorrected first color and a device for activating at least one further light emitting element which emits a color other than the first color , to produce a corrected first color . an array of corrected display modules and a method of correcting a color in a display module are also disclosed .