Source: https://nerdlypleasures.blogspot.com/

When in 1977 the Apple ][ started to establish the age of microcomputers, it was the first machine that - assuming an NTSC version - could display in color.

But the really interesting thing is, that the composite signal of the machine actually used a hack, which exploits low level technical color artifacts, which were normally supposed to be suppressed on old CRT monitors.

The Great Hierophant - whose identity unfortunately remains a mystery - has dedicated himself to the topic in detail and written an article about the technical background and engineering ingenuity.

Anyone who has ever dealt with the generation of more modern VGA or HDMI signals will be amazed by the creativity of the engineers of that era. 

A great article, absolutely worth every minute of reading time.