script for "magic pencil/brush"

HI all!
I’m not familiar with scripts, but, would there be a way to write a script to create the magic color pencil.brush effect, meaning to have a color constantly changing in the way, magic pencils aka pencils with multiple color leads do? I know this a bit of an outlandish and peculiar request, but I just need to find a way to do this, other than actually doing the animation on paper with such pencils…
ps: of couse, if someone can think of a method to create this effect otherwise, that would be great too! maybe a color changing module or a multicolored texture?