The Apple II color hack - How Wozniak created color from monochrome (ntsc-color-hack.lovable.app)

How Steve Wozniak exploited TV timing to bring color to the Apple II

The atari 8-bits did a similar thing, it was called "artifacting" [1] and was used (amongst other things) by Ultima IV [2] to produce a high-res 'colour' display - at least if you lived in the USA. It was more of a "mess" if you lived in the UK...

1: https://www.atarimania.com/faq-atari-400-800-xl-xe-what-is-a...

2: https://thekingofgrabs.com/2022/12/12/ultima-atari-8-bit/