colour bar

• color bar

colour bar (plural colour bars) (British spelling)

1. The segregation of people of different colour or race, especially any barrier to black people participating in activities with white people.
   • 1994, Nelson Mandela, Long Walk to Freedom: The Autobiography of Nelson Mandela, London: Abacus, published 2010, page 83:

     That first morning at the firm, a pleasant young white secretary, Miss Lieberman, took me aside and said, ‘Nelson, we have no colour bar here at the law firm.’

   • 2010, Christopher Hitchens, Hitch-22, Atlantic, published 2011, page 205:

     In my hometown of Portsmouth there was a riot in 1943, with the locals scorning attempts by American military policemen to enforce a color bar in the pubs.

   • 2020 October 7, “Network News: Plaque at Chatham honours colour bar pioneer”, in Rail, page 26:

     A plaque commemorating the memory of British Rail guard Asquith Xavier, who broke the colour bar at Euston station in 1966, was unveiled at Chatham station on September 24.

2. (printing) A pattern of varying tonal density that enables visual and numeric comparisons to be made across multiple printed sheets or pages.
3. (jewelry) A layer of good jewellery-quality opal within a rough opal.

• color line