In many cultures, red is regarded as a warning color.
First of all, in China, red is often used as the color of blessing and celebration, and it also represents stop and vigilance. In western culture, red is widely regarded as a warning color and is usually used in dangerous situations. Therefore, it is considered a common cultural custom to use red as the color of danger signals.
The human visual system is particularly sensitive to red.
Secondly,. Red is the color with the longest wavelength in the spectrum, so in a dark environment, the brightness of red is higher than other colors, and it is easier to be perceived by human eyes. In addition, there are two kinds of cone cells in human retina, one of which is more sensitive to red light. This means that we can perceive red more clearly and associate it with danger signals.
Therefore, from two aspects of culture and physiology, red has become an ideal color for danger signals. In modern society, we can see the use of red as a danger signal in various occasions, such as traffic lights, fire alarms, medical devices and so on. By using red universal symbols, we can convey danger signals to people more effectively and help them protect themselves and avoid danger.