In this video the late "wet-on-wet" oil painter Bob Ross demonstrates painting using two colors black and white and a bit of "shadow" colors to show that even if you are color blind you can still paint and the result is still a beautiful piece of artwork that one can get proud of.
Maybe this kind of technique is good for aspiring painters who only have a small budget because they would only use two colors for making their own traditional oil painting.
I do not know yet if I can do the same but this is interesting if I would do it digitally here in my laptop but I guess it will make the work faster as I will not blend many colors but of course it will look like you are really color blind if you will look at the final result.
Bob Ross is a damn genius!