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 and blue – the chrominance signal) with the fourth providing a high-resolution monochrome image (the luminance signal) which was still required as many viewers still watched on monochrome receivers. The final colour picture was created by combining the chrominance and luminance signals, but the technicians simply switched off the colour tubes whilst this dispute took place.
This meant that even though colour equipment was available, all shows were recorded and broadcast in black-and-white, thus denying the ITV companies the ability to sell airtime at the higher value that colour transmissions dictated.
In some film sequences for location shots in these programmes (shot in colour), the colour signal from the telecine machine had to be switched off in the vision mixing desk before being recorded to tape, but this was partly unsuccessful, leading to some film sequences being recorded with an odd array of pale colours (as for items where the colour is a mix of two primary colours, only one primary colour would show). This is prominent in the second series of Hadleigh, for example.
The first Coronation Street to be broadcast in colour was transmitted on 3 November 1969, but due to the strike, some 1970–71 episodes, including the one featuring Valerie Barlow's electrocution, were recorded in black-and-white. The last black-and-white edition was shown on 10 February 1971, although the episodes transmitted on 22 and 24 February 1971 contained black-and-white film inserts.
All of ITV's programmes were broadcast in black-and-white throughout this period, including scheduled repeats and regional programmes.
The strike was called off on 2 February 1971 with all colour production and transmissions resuming on 8 February except for some ITV regions continuing to broadcast in black-and-white until the following dates: Westward Television (22 May 1971), Border Television (1 September 1971), Grampian Television (30 September 1971) and Channel Television (26 July 1976).
There was also a short dispute two years later in early 1973; this affected both BBC channels as well as ITV.
Shows affected by the ITV colour strikeEdit
- Budgie (LWT) (the first four episodes of series one)
- Please Sir (LWT) (the last three episodes of series three)
- Upstairs, Downstairs (LWT) (the first half of series one was made in black-and-white; the first episode was later reshot in colour. The remaining black-and-white episodes are often not shown in overseas syndicated broadcasts)
- The Big Match (LWT) (22 November 1970 - 7 February 1971)
- World of Sport (LWT) (21 November 1970 - 6 February 1971)
- The Golden Shot (ATV) (episodes 10 - 21 of series three)
- This is Your Life (Thames) (first half of series eleven)
- Timeslip (ATV) (episodes 23 & 24)
- Doctor at Large (LWT) (the first six episodes)
- On the Buses (LWT) (the second half of series four, plus the Christmas special 1970)
- Bless This House (Thames) (the first seven episodes of series one, the opening titles to the eighth episode was transmitted in black-and-white)
- Carry On Again Christmas (Thames)
- All Star Comedy Carnival (LWT) (1970)
- Crossroads (ATV) (all episodes transmitted on and between Tuesday 17 November 1970 and Friday 12 February 1971)
- Coronation Street (Granada) (all episodes transmitted on and between Monday 16 November 1970 and Wednesday 10 February 1971. In addition, the short segment for the All Star Comedy Carnival was recorded and transmitted in black-and-white on Friday 25 December 1970 and the episodes transmitted on Monday 22 and Wednesday 24 February 1971 had contained black-and-white location inserts)
- Dear Mother...Love Albert (Yorkshire) (all six episodes of series three)
- Hine (ATV)
- David Nixon's Magic Box (Thames) (episodes 1 to 8 of series two)
- The Mind of Mr. J.G. Reeder (Thames) (all of series two apart from 'Man with a Strange Tattoo')
- The Trouble with You, Lilian (LWT) (all but episode 1)
- Six Dates with Barker (LWT) (episode 3)
- A Family at War (Granada) (episodes 12 to 19 of series two)
- The Dickie Henderson Show (ATV)
- Mr Digby, Darling (Yorkshire) (all six episodes of series three)
- Nearest and Dearest (Granada) (episodes 2 to 8 of series five)
- Never Mind The Quality, Feel The Width (ABC/Thames) (episodes 1, 3, 4 & 7 of series five)
- Hadleigh (Yorkshire) (episodes 1, 2, 8, 9 and 13 of series two – the last five black-and-white episodes of that series to be made)
- The Misfit (ATV)
- Elephant's Eggs in a Rhubarb Tree (three out of six editions)
- Girls About Town (ATV) (episode 4 to 7 of series two)
- Freewheelers (Southern) (episodes 6–11 and 13 of series five)
- The Sooty Show (Thames)
- The Benny Hill Show (Thames) (3 specials – December 23 1970, January 27 1971 and February 24 1971) 
- Queenie's Castle (Yorkshire) (episodes 3–6 of series one)
- Public Eye (Thames)
- Opportunity Knocks (the final four episodes of series ten)
- The Frighteners (LWT) (two plays out of thirteen)
- "The TV Room". Tvfeatures.thetvroomplus.com. 28 January 2002. Archived from the original on 27 May 2012. Retrieved 29 November 2012.
- Up the Maggies. "Notts on the box – The 1970's". Homepage.ntlworld.com. Archived from the original on 13 October 2012. Retrieved 29 November 2012.
-  Archived 11 February 2007 at the Wayback Machine
- See booklet included with series DVD, Network, 2017