Blue idioms are relatively common in English and, as is often the case with idioms, they usually have nothing to do with the colour blue.
Please be aware of the problems of using idioms incorrectly. This post will help you with this.
There is also a video for those of you who prefer to watch content.
Let’s look at some blue idioms in detail.
Once in a blue moon
Rarely, hardly ever.
Apparently, there is a rare set of conditions that will result in the moon appearing to have a blue shade.
Example: “Since he’s been at university, I only see my son once in a blue moon – usually when he needs money.”
Out of the blue
In this case, the ‘blue’ in the idiom is the sky. If you imagine a clear blue sky and then suddenly, out of nowhere, a storm blows up, this is the basis of this idiom.
Example: “The chairman’s resignation came out of the blue – completely unexpected.”
A bolt from the blue
Sudden and unexpected.
Similar to the previous idiom, the ‘blue’ is the sky. The bolt from the blue is unexpected lightning frim a clear blue sky.
Example: “The chairman’s resignation was a bolt from the blue – completely unexpected.”
Sad or depressed.
This association is often used in modern songs, although it goes back a lot longer than modern music.
Example: “He has been feeling blue ever since his girlfriend left him.”
Related to royalty or nobility.
This expression comes from the fact that high-born people didn’t have to work outdoors. People who worked outdoors got suntanned skin and people who didn’t had fairer skin. If the skin was pale enough, you could see the blood vessels underneath, which looked blue, rather than red.
Example: “She thinks she’s better than everyone else because she has blue blood in her veins.”
Boys in blue
This is an easy one to understand, as the British police have blue uniforms. This expression is one of the more friendly ones in use to describe the police force. As you can see from the photo, other police forces around the world also have blue uniforms.
Example: “The boys in blue successfully captured the robbers.”
Black and blue
After a severe beating, the bruising will appear as dark blotches on the skin, looking black and blue.
Example: “He was black and blue after losing the boxing match.”
Blue in the face
Pale from exhaustion or strain.
Example: “I’ve explained it to my boss until I was blue in the face but he still doesn’t understand the situation!!”
Blue collar worker
This is a rarity, as the blue in this idiom does indeed refer to the colour blue. Whereas office workers usually wear a suit and tie (and are called white collar workers), manual workers tend to wear blue overalls and are referred to as blue collar workers.
Example: “Blue collar workers are on strike for better working conditions.”
You can use this expression in two separate ways, one positive and the other cynically and sarcastically.
In the positive sense, it is used to indicate that someone is a current favourite in certain circles.
In a negative case, it can be used to pour scorn on someone for apparent receipt of benefits and favours.
Positive Example: “After winning the competition, he quickly became the blue-eyed boy of the race circuit.”
Negative Example: “You got another pay rise? Aren’t you the bosses’ blue-eyed boy ^^”
Blue Idioms Summary
As you can see, there is a diverse variety of blue idioms and expressions.
Did I miss any of your favourite blue idioms? Please use the comments to tell me.