Black and blue : To be bruised either because of a beating or otherwise.

I am going to beat you black and blue.

Catch someone red-handed : To get caught doing something wrong, illegal or unlawful.

He was spying on the minister and the police caught him red-handed.

Green with envy : To feel extremely jealous.

Green with envy : To feel extremely jealous.

Green with envy : To feel extremely jealous.

His expensive car made me go green with envy.

Off colour : A term used for someone looking weak or unwell.

He’d recovered from the attack but he still looked off colour.

Once in a blue moon : To refer to something that occurs very rarely.

I meet him only once in a blue moon.

See red : To be extremely angry about something

After she betrayed him, he was seeing red.

To show your true colours : When someone shows their true colours, they reveal the kind of person they really are.

Only in times of need do friends show you their true colours.

To pass with flying colours : To pass something with flying colours is to do very well.

I had thought I wouldn’t clear the exams but I passed with flying colours.

Whitewash : To white wash something is to cover up its flaws.

The Indian government has been accused of trying to whitewash the Commonwealth games scandal.

Golden opportunity : A golden opportunity represents an opportunity that is very hard to come by and rather unexpected.

The deal was a golden opportunity and anyone would have been foolish to have not signed it.