Colour control of backlighting system

In an embodiment, the invention provides a method of color control in a backlighting system comprising a plurality of LED light sources (210), a plurality of color sensors (206), a plurality of PWM controllers (218), and a video input for receiving video data. The plurality of light sources is activated during a first operative mode to produce white light. The spectral content of the white light is measured and a first duty cycle ratio calculated and sent to a PWM. The plurality of light sources is controlled during a second operative mode to produce white light. The brightest LED is determined and a second duty cycle ratio is calculated. The method of colour control may be used to dim sections of the backlight to improve contrast and reduce power consumption, it may also be used to change the intensity or colour point of the white light.