I find
colorful metaphors hard on the ears when overused or used incorrectly.
They always sound offensive to me when aimed in anger.
Whether you tell someone you find it offensive or not depends on the situation, IMO.
If it's your friend or family, why not?
If it's a stranger, why bother? Freedom of speech and all.
If it's the work environment, maybe.
As a secretary, when someone calls to vent with colorful metaphors; I send them to the boss.
It's probably his fault anyway.
"Peshat is what I say and derash is what you say." --Nehama Leibowitz