Meaning of “sees fifty shades of ...” in this context

The thing is, everyone’s peeves and crochets are different. People who couldn’t care less about “could care less” will, faced with the use of “impact” as a verb, geschrei the house down, and that mob that sees fifty shades of red, scarlet, and carmine over the relatively newfangled use of “begs the question” to mean “raises the question” may well pass by a “comprised of” without so much as batting an eye.

— Dreyer's English: An utterly correct guide to clarity and style, Benjamin Dreyer pub. Random House 2019 [My emphasis]

Could anyone help me understand “sees fifty shades of ...” in this paragraph?

To "see red" is "Become very angry, as in I saw red when I learned they had not invited Tom and his family. The precise allusion in this term is not known, but it probably refers to the longstanding association of the color red with passion and anger" from dictionary.com.

"fifty shades of red, scarlet, and carmine" would indicate the mob being angry in different ways, about different things, with a nod to Fifty Shades of Grey (see Wikipedia link).