Colour Strike Colour Strike The Colour Strike was an industrial action by technicians at all ITV companies from 13 November 1970 to 8 February 1971 (although some shows made during this period in black and white were having their first transmission as late as December 1971) who, due to a pay dispute with their management, refused to work with colour television equipment. At that time ITV had recently switched to colour transmissions, requiring the individual companies to invest heavily in new equipment. Early colour television studio cameras consisted of four tubes to relay the picture: three were receptive to colour (red, green
Colour recovery frequency, known as the "colour subcarrier". Black and white televisions do not decode this extra colour information in the subcarrier, using only the luminance to provide a monochrome picture. However, due to limited bandwidth in the video channel, the chrominance and luminance signals bleed into each other considerably, resulting in the colour information showing up visibly as Chroma Crawl, or Chroma dots on black & white TV sets. This is normally considered a nuisance in analogue broadcasting. However, since telerecordings were made from black & white TV screens and technicians at the time often decided not to apply a filter