Out of the blue = without warning, unexpectedly. Sarah called out of the blue. I hadn’t spoken to her for 3 years!
To feel blue = to feel depressed. I always feel blue in January.
To be green with envy = to feel very envious. She’s going on holiday to The Bahamas, I’m green with envy!
To give/get the green light = to give or get permission. We’ve been given the green light to start the project next week.
The grass is always greener (on the other side) = A situation always seems better from the other perspective / you always want what you don’t have. I wish I was self-employed and could be my own boss but he wishes he had the security of a permanent job – the grass is always greener!
A white lie = a lie told to be kind. She asked me if she’d put on weight. Of course, I told a white lie and said “no, you haven’t!”
To be black and white = to be straightforward, very clear. The agreement is black and white, pay 10% every month or receive a fine.
A grey area = a situation which is unclear. Behavioural management is a grey area, there are no guidelines for teachers in the school.