PAL uses the color info from a prior scan line in addition to the color info on the current scan line to establish a given pixel color.

If one is clever about changing pixel colors in a way synchronized with the display, more than 16 colors will be seen.

The C64 only has 16 colors. Fixed colors.

Abusing TV was, and can still be, interesting.

On the older machines, a gain of new colors was a big deal.

In this case, it still is a big deal, given how craptastic the CGA is.