The first arcade game to incorporate color was Computer Space, manufactured by Nutting Associates and released in November 1971.
Wimbledon (1973, Atari) or Gotcha (1973, Atari) used color overlays for green court/red ball. True RGB color arrived with Space Invaders (1978, Taito) via colored cellophane strips, then Galaxian (1979, Namco) with hardware RGB sprites.
Computer Space remains the historic "first color" milestone, however modest.