A horse of a different color

A different kettle of fish / Quite another cup of tea / A different ballgame / Another pair of shoes / Be another matter entirely!

Essere un altro paio di maniche

Essere un'altra faccenda / Essere un altro discorso / Essere tutta un'altra musica / Essere un discorso a parte

Meanings

Another matter altogether; a completely different situation; a change from what one thought was being talked about or considered

Examples

Anyone can be broke, but to steal is a different ballgame

Tutti possono trovarsi in difficoltà prima o poi, ma rubare è un altro discorso

I want to know why you didn't go to school yesterday; the fact that today you got an A in the math test is another pair of shoes

Voglio sapere perché non sei andato a scuola ieri; il fatto che oggi tu abbia preso 9 nella verifica di matematica è un altro paio di maniche

I thought she was dating a guy young enough to be her son and then I found out he is her son. Well, that's a horse of another color

Pensavo che uscisse con un ragazzo che poteva essere suo figlio e poi ho scoperto che è veramente suo figlio. Beh, allora è un altro paio di maniche

Origin

Horses are registered at birth and the registration includes a record of their color. When a horse trades hands due to sale, the registration is also transferred. Sometimes the color recorded on the registration may not match the actual color of the horse leading one to suspect the horse is not the one in the registration. Horses sometimes change color as they age, just as some people's hair changes color, but more likely the horse is not the one represented on the registration and is actually an entirely different horse.

In Shakespeare's “Twelfth night” we find a similar expression when Maria says: ”My purpose is, indeed, a horse of that colour”. The current sense is believed to have originated in the United States in the late 18th century and then was adopted in Great Britain. It was stated by Anthony Trollope in “The Last Chronicles of Barset” (1867): “What did you think of his wife? That's a horse of another colour altogether”