Teletext art
Pictures drawn in teletext's mosaic graphics — 40 characters wide, eight colours, no exceptions.
Teletext could split each character cell into a 2×3 grid of blocks, giving roughly 80×72 dots for the whole screen. Colour changes were not attributes but control characters that occupied a cell themselves, so every new colour punched a hole in the picture. Coaxing logos, weather maps and portraits out of that was a craft in the same family as PETSCII and ANSI art.
For years the broadcasters' own graphic artists did most of the drawing, but the form has enjoyed a second spring among hobbyists recreating old pages and making new ones, sometimes broadcast through homebrew teletext services or shown in emulators. The restriction is the point: there is no shortcut to more colours.