American film and television studios terminated production of black-and-white output in 1966 and, during the following two years, the rest of the world followed suit.
By the 40th Academy Awards, held on April 10, 1968, not only were the winner (In the Heat of the Night) and all four of the other nominees (Bonnie and Clyde, Doctor Dolittle, The Graduate and Guess Who's Coming to Dinner) were in color but, because studios were no longer producing black-and-white films, the awards for Best Cinematography, Best Art Direction and Best Costume Design were merged into single categories rather than having a distinction between color and monochrome.
[2] By late September 1964, the move to potential all-color programming was being seen as successful[3] and, on March 8, 1965, NBC confirmed that its 1965–66 season will be almost entirely in color.
Other than a very small number of major films that the studios were willing to publicize — The Fortune Cookie, Is Paris Burning?, Who's Afraid of Virginia Woolf?
A similar situation had occurred 37 years earlier, in 1929, when studios stopped production on mid-completion silent films and ordered the addition of dialogue.