Mac and cheese was considered a really fancy food at one time, during the start of modern-style restaurants in America in the early-mid 1800s, it was the go-to dish to be served to you in a fancy restaurant (because all restaurants were a bit fancy then) in America.
The same person who puts it on a pizza.
Butter can also be white based on the milk/cream it is made from. My shop buys a lot of farm fresh milk for ice cream. We use some of the cream to make butter. for a while, it was completely white because the cows only got hay but we recently had good rain and now that they got fresh grass the butter is yellow.