The phrase "a horse of a different color" means something that is completely different or distinct from what was previously discussed or considered. It originated from a phrase used by Shakespeare to refer to the same matter, which later evolved in the 1800s to point out difference rather than similarity. Examples of its use include describing a boyfriend turning out to be a brother, Clinton being distinct from other politicians, and jokes that hurt people being a different matter than jokes that don't.

1. Horse of a different color”