The idiom for the color "red" is "seeing red." This phrase is commonly used to describe a state of anger or frustration. For example, if someone is extremely upset, they might say, "I'm seeing red.

The idiom "seeing red" has its origins in the physiological response of the human body. When a person is angry or excited, their blood vessels can dilate, causing their face to turn red. This physical reaction is what the idiom refers to. The phrase has been in use since at least the 17th century, as evidenced by its inclusion in various historical texts.

Data from psychological studies support the use of this idiom. A study published in the journal "Emotion" found that red can indeed evoke feelings of anger and aggression. Researchers conducted experiments where participants were exposed to different colors and then asked to rate their emotional responses. The color red consistently led to higher levels of anger and frustration compared to other colors.

Furthermore, the idiom "seeing red" is widely recognized and understood in American culture. It is a part of the everyday language and is often used in both formal and informal contexts. This widespread acceptance and usage of the idiom highlight its cultural significance and its effectiveness as a means of conveying the emotional state of anger or frustration.