Ceefax, the BBC's teletext service, ran from September 1974 to the 2012 switch-off. A page is forty columns by twenty-four rows sent in the blanking lines of the TV signal. Pictures are block mosaics: each character cell is a two-by-three grid of blobs in one of eight colours.
Colour was per character, not per pixel, and a colour change was itself a control character that took up a cell and printed black. So every teletext figure is stair-stepped, flat, and striped with little gaps wherever one colour meets another. Nine people edited the whole service.
The figure is rasterised at sixel resolution, eighty by seventy-two, and every character cell takes the colour most of its six sixels vote for. Walking along each row, a cell whose colour differs from the last is printed black instead, the control code. Header, double-height headline and fasttext bar are the three-by-five font at twice the scale.