I once heard someone trying to claim that the phrase "calling a spade a spade" was rascist.
I was obviously kidding about the racist thing but it's based on personal experience. I went to an urban high school. Bus driver was arguing with some of the kids about something and ended up using that phrase about pot calling the kettle black and the whole bus (except for me the lone white guy) exploded, carrying on about her being racist.
It was...something. hah