copperbadge:

Well, NPR seems to think it’s because American cheese makers are more determined to fake it. 😀

Apparently English cheese used to be orange from the beta carotene in the cows’ diet; cheese makers in the 17th century started skimming off the fat before making the cheese, which skimmed off the color as well, so they started dyeing it to look like The Quality Stuff. This carried over to colonized America, where in all but New England they continue the tradition to this day. Presumably sometime between the 17th century and now, European cheese makers stopped dyeing their cheese, which is why non-American cheddar is paler. 

Americans do have a pale cheddar, usually called White or Irish Cheddar, and it’s not uncommon, like I can buy white cheddar in most grocery stores. It’s usually less creamy and sharper than orange cheddar, but not always. 

Americans associate yellow or orange with “quality dairy” presumably for the same reason 17th century English did, because the orange came from fat from high-quality milk. In the early 20th century margarine was dyed yellow to look like butter, and when the dairy council protested and eventually outlawed this in the midcentury, margarine was packaged with dye pellets that you kneaded into it to turn it yellow after you’d bought it.

And this has been your Dairy History™ for the day!