and claimed the colour was rose gold. It’s pink, was the common reply. But as this piece shows ( The Semiotics of “Rose Gold” – The New Yorker), rose gold is a specific material. It refers to an alloy of gold to which copper has been added. For that matter, white gold, which is an alloy with nickel or manganese, is also a specific material. Jewelers know this, of course, and Apple is smart to associate with the metal (gold) vs the colour.
The New Yorker piece is fascinating. Worth reading, especially if you are skeptical about the colour.