She has been off colour recently.

她最近气色一直不好。

You are off colour; you'd better take a rest.

你气色不好，休息一下吧。

Doctor:Right. Well, we'll just have a look. Uh, Sir, has he been a bit off colour lately.

医生： 好。我们就来看一看。唔，先生，他近来是不是精神有点不好（身体有些不舒服）

He denies making off-colour remarks about women.

他否认曾经说过关于女性的污言秽语。

The firework went off in a cascade of colour.

烟火散开像一片五彩缤纷的瀑布。