off-colour

adjective

1. not having the usual or standard color: an off-color gem.
2. of doubtful propriety or taste; risqué: an off-color joke.
3. not in one’s usual health: to feel off-color.

adj.see off-color. adj.1858, from off (adv.) + color (n.); originally used of gems; figurative extension to “of questionable taste, risqué” is American English, 1867.