Hate to sound like a fool, but I've read here, in earlier days, that there was no such thing as a 'paint gene', and like the frizzle you're either frizzle or not. I've read here, where 'black to black' matings of blacks from paint do not and 'will not' produce paint, I've proven that theory wrong. Same goes for white. Also read here where you cannot produce paint from a paint to a white american mating, I've proven this incorrect too. Read here where to incrrease the size of spots one needs to breed to black, bunch on nonsense. I know nothing of holes and windows and will leave that to those building houses.
I've been breeding serama for 10 years and know to expect the unexpected. Same with my paints.