Why are cows black and white?

1. There are many kinds of cows, only Dutch black-and-white cows are black-and-white cows. Because of the high milk yield, this kind of cow is raised all over the world, so it is raised everywhere and becomes the dominant variety. 2. Coat color is formed as a variety feature in breeding, so from the genetic point of view, its genotype is like this. But how many pairs of genes control this color? Is it dominant inheritance after all?