Why are the colors of traffic lights red, yellow and green?
I don’t know if you have ever thought about why you choose red, yellow, and green for the color of traffic lights. However, these 3 colors have been chosen. Let’s explain this for everyone. Let’s talk about this problem. Let's briefly look at how this kind of traffic light appears.
It was in 1868 that the world's earliest traffic lights appeared on the streets of London, England. At that time, the signal lights had only two colors, red and green, and they were far from the current street signal lights. They could only rely on the police to stand next to the signal lights and control the color change by pulling a wrench. After that, this kind of traffic lights slowly became popular all over the world. It was not until 1920, in Detroit, the United States, that a yellow signal light was added for the first time to remind drivers that the signal light was about to change from a green light to a red light.
So why use the three colors of red, yellow and green instead of other colors?
This must start with red. Among various colors, red is the easiest to attract people's attention. It may be because red is the color of blood. In various cultures, red has always been given the meaning of "warning" and "forbidden". Therefore, it is only natural to choose red for the signal light that represents the prohibition of traffic.
So why use green to represent passage? This is because at that time, people generally believed that red and green, like black and white, were a pair of complementary colors. Since the red represents the prohibition of passage, it is reasonable to use the opposite green to indicate the passage is permitted.
And yellow, a color between red and green, was chosen to act as an intermediate signal light to indicate that the traffic lights are about to change.
Finally, let me tell you a little secret. The traffic lights in most countries are not pure red and pure green, but slightly yellowish red and slightly blueish green. This is mainly to make some people suffer from redness. People who are green-blind can more easily distinguish the color of the signal light.
