Be green with envy
To be green with envy is to be unhappy because you wish you had something that someone else has.
- Margaret will be green with envy when she sees your new car.
Have green fingers
When you have green fingers, you are good at growing plants.
- Alice has green fingers. Look at her garden.
Once in a blue moon
If something happens once in a blue moon, it happens very rarely.
- I visit them once in a blue moon.
Scream blue murder
To scream blue murder is to shout very loudly because you are in great pain or you are very angry.
- The little girl screamed blue murder while the doctor tried to give her an injection.
Talk a blue streak
To talk a blue streak is to talk a lot without pausing.
- The boy didn’t talk until he was five and then he started talking a blue streak.
Turn the air blue
To turn the air blue is to use a lot of swear words because you are angry.
- When he discovered that he had been cheated he turned the air blue.
Until/till you are blue in the face
This informal expression is used to suggest that there is no point in doing something because you will not succeed.
A shrinking violet is a very shy person.