A) The portion of a colour video signal that resides on the backporch between the breezeway and the start of active video that contains a sample of the colour subcarrier used to add colour to a signal. It is used as a colour synchronisation signal to establish a reference for the colour information following it and is used by a colour monitor to decode the colour portion of a video signal. The colour burst acts as both amplitude and phase reference for colour hue and intensity. The colour oscillator of a colour television receiver is phase locked to the colour burst. b) A nine-cycle-NTSC burst of colour subcarrier which is imposed on blanking after sync. colour burst serves as the reference for establishing the picture color.