Windows 1.0 (1985) was Microsoft's first graphical shell, running tiled windows over MS-DOS. Limited to a fixed hardware palette, it couldn't display its signature desktop green directly — so it dithered it, tiling 8×8 blocks of bright green with 4×4 patches of cyan to blend a softer shade the hardware couldn't name. Depending on how you average that pattern, the result lands near #57ff81 (a simple pixel average) or #57ff9a (averaged in linear light, gamma-corrected).