50 years ago today, after a boycott by passengers, the Bristol Omnibus Company ended their ban on employing ethnic minorities as bus drivers and bus conductors. Newsnight had a report on the matter last night.
The "colour bar" was supported by region of the Transport and General Workers Union (as Unite the Union was then known.)
Such a mentality in the trade unions was not unusual, at home or abroad. In South Africa the white trade unions keenly supported the "pass laws" which meant their members did not have to face a competitive labour market.
There were other restrictions which had an indirect racist impact.
Most notoriously the Dock Labour Scheme (abolished by Margaret Thatcher in 1989) effectively excluded black people from becoming dockers. The jobs were passed down the generations to the sons of existing dockers. The Transport and General Workers Union had control of recruitment.