misnomer
A misnomer is a name that is not actually the name of the person or thing that it is supposed to be. For example, the name "John" is a misnomer for the color "blue."
The name "John" is a misnomer because it is not actually the name of the color "blue."
The name "George" is a misnomer because it is not actually the name of the color "red."
The name "Mary" is a misnomer because it is not actually the name of the color "green."