Apple II (1977) did an early version of this; it essentially had purple and green addressable colors in each pixel. With both on in a single pixel you got white

Apple II (1977) did an early version of this; it essentially had purple and green addressable colors in each pixel. With both on in a single pixel you got white text, but could also leverage two adjacent pixels, one with purple and one with green, to produce a half-pixel offset that could produce a smoother diagonal line than typical fixed coordinates. https://en.wikipedia.org/wiki/Subpixel_rendering https://en.wikipedia.org/wiki/Subpixel_rendering