Here's how it works:
* When someone is very angry or upset, their face may turn red or flushed.
* If someone is struggling hard to do something, they might hold their breath and strain, which can cause their face to turn a bluish color due to lack of oxygen.
* This imagery is used to describe the feeling of exhaustion and frustration that comes from putting in a lot of effort without achieving the desired result.
Here are some examples of how the idiom is used:
* "I argued with him until I was blue in the face, but he wouldn't listen."
* "She tried to explain it to him, but he just stared at her blankly, and she was blue in the face."
* "I've been working on this project for hours, and I'm blue in the face, but I still can't get it right."
The idiom "blue in the face" is used to convey a sense of:
* Effort: The person has put in a lot of effort.
* Frustration: The person is frustrated because they haven't succeeded.
* Exhaustion: The person is exhausted from trying.
It's important to note that the phrase "blue in the face" is an exaggeration. People's faces don't actually turn blue from trying too hard. However, the idiom is effective in conveying the feeling of intense effort and frustration.