horse of a different color

Also found in: Acronyms, Wikipedia.

horse of a different color

Something completely different or separate, especially in comparison to something else. I've always found math to be easy, but calculus is a horse of a different color.
See also: color, different, horse, of

horse of a different color, a

Also, a horse of another color. Another matter entirely, something else. For example, I thought that was her boyfriend but it turned out to be her brother-that's a horse of a different color . This term probably derives from a phrase coined by Shakespeare, who wrote "a horse of that color" ( Twelfth Night, 2:3), meaning "the same matter" rather than a different one. By the mid-1800s the term was used to point out difference rather than likeness.
See also: different, horse, of

horse of another/different color, a

A different affair altogether. This term was more or less invented by Shakespeare, who in Twelfth Night (2.3) wrote, “My purpose is, indeed, a horse of that colour,” meaning, my aim is indeed something like that. Eventually this was changed to difference rather than likeness, as in Anthony Trollope’s Last Chronicles of Barset (1867): “What did you think of his wife? That’s a horse of another colour altogether.”
See also: another, different, horse, of