horse of a different color
有所不同的事物
口語·強調完全不同的事物
英文釋義
Something that is completely different or unrelated; a separate or distinct matter
例句
That's a horse of a different color; we were talking about work, not hobbies.
典故來源
源自賽馬中不同顏色的馬代表不同事物，比喻完全不同的情況或話題。