The word “skittles” goes back centuries and defines a form of lawn bowling from which all other bowling games are descended. How do you copyright a common noun?
Might as well imagine a colloquy between Trump and his accountant:
“Buy `buy’, Smathers”
“Mr. Trump, do you mean `goodbye’?”
“No, I mean buy the word `buy’. I don’t want anyone else to use it again.”
You make an interesting point about the origins of the word .... However Mr. Trump referenced a Bowl of Skittles along with a picture .... No mistaking the reference ...