He gets up in the morning and he paints 200,000 strokes

There is 10% chance he will pick a white canvas and paint with black.
There is 10% chance he will pick a black canvas and paint with white.
But most likely (80% chance) he will pick a black canvas and paint with random colors.
When he picks the random colors, he will choose a pallet of 2-7 totally random colors and randomly pick one of them them every 400 strokes.
He repeats that 500 times and then he stops.