This was quite a lovely surprise! The music was soothing, and the Hungry Cat Style Picross rules with multiple colors is a joy.
Dumb idea which I haven't thought through what the gameplay ramifications might be. Bob Ross was famous for using the wet on wet technique, which makes it really easy to blend colors on canvas as everything is obviously still wet. Just keep layering on that paint. Would there be some kind of way to give picross rules that get the player to blend colors somehow? Whether on the canvas or on the palette?