Traffic Light Color

　Traffic light colors are based on universal standard. According to the International Commission on Illumination (CIE), colors that can be used for traffic lights are "red, yellow, green, blue, purple and white," but we use only "red, yellow and blue-green" in most cases. Although a green light might look completely green, the actual color is usually blue-green. Since our eyes are sensitive to green, we view the blue-green light to be green light.

　Also, Japanese people refer to a green light as "青信号 (blue light)," though, we look it's green. It is said that the reason is that we represented all colors from green to blue using only the word "blue," or we thought the contrast of red is blue.

　信号機の色は世界共通です。国際照明委員会（CIE）によると、信号機に使える色は「赤・黄・緑・青・紫・白」の6つですが、我々は大抵「赤・黄・青緑」を使います。青（緑）信号は完全に緑色に見えるかもしれませんが、実は青緑であることが多いです。我々の目は緑色を敏感に感じるようになっているので、青緑色が完全に緑に見えるのです。

　また、日本では青（緑）信号のことを、緑色に見えるにも関わらず、青信号と呼んでいます。これは、日本では昔から緑から青にかけての色を全て「青」と表現していたことや、「赤」の対比が「青」とされてきたことに起因すると考えられています。

• Traffic Light Color
• The colors of traffic lights.

• Traffic light colors are based on universal standard.
• The traffic lights' colors are based on universal standards.

• According to the International Commission on Illumination (CIE), colors that can be used for traffic lights are "red, yellow, green, blue, purple and white," but we use only "red, yellow and blue-green" in most cases.
• According to the International Commission on Illumination (CIE), the original colors that can be used for traffic lights to direct or control the traffic, are red, yellow, green, blue, purple and white colors. However, we just use only the red, yellow and blue-green colors in the most of cases.

• Although a green light might look completely green, the actual color is usually blue-green.
• Although Truly, the actual color of the blue light is blue-green almost all the time.

• Since our eyes are sensitive to green, we view the blue-green light to be green light.
• Since our eyes are sensitive to the green color, it translates the blue-green light into the green one.

• Also, Japanese people refer to a green light as "青信号 (blue light)," though, we look it's green.
• Also, Japanese people refer to a green light as "青信号 (blue light)," though due to the view of the green color.

• It is said that the reason is that we represented all colors from green to blue using only the word "blue," or we thought the contrast of red is blue.
• It is said that the "blue" word represents the blue level, or we can understand that the contrasting color of the red is the blue.

• Traffic Light Color
• Traffic Light Colors

• Traffic light colors are based on universal standard.
• Traffic light colors are based on a universal standard.

• According to the International Commission on Illumination (CIE), colors that can be used for traffic lights are "red, yellow, green, blue, purple and white," but we use only "red, yellow and blue-green" in most cases.
• According to the International Commission on Illumination (CIE), colors that can be used for traffic lights are "red, yellow, green, blue, purple and white," but we use only "red, yellow and blue-green" in most cases.

• Although a green light might look completely green, the actual color is usually blue-green.
• Although a the green light might look completely green, the it's actually color is usually blue-green.

• Since our eyes are sensitive to green, we view the blue-green light to be green light.
• Since our eyes are sensitive to green, we view the blue-green light to just be green light.

• Also, Japanese people refer to a green light as "青信号 (blue light)," though, we look it's green.
• Also, Japanese people refer to a green light as "青信号 (blue light)," though, we look know it's green.

• According to the International Commission on Illumination (CIE), colors that can be used for traffic lights are "red, yellow, green, blue, purple and white," but we use only "red, yellow and blue-green" in most cases.
• According to the International Commission on Illumination (CIE), colors that can be used for traffic lights are red, yellow, green, blue, purple or white, but we only use red, yellow and blue-green in most cases.

• Although a green light might look completely green, the actual color is usually blue-green.
• This sentence is perfect! No correction needed!

• Since our eyes are sensitive to green, we view the blue-green light to be green light.
• This sentence is perfect! No correction needed!

• Also, Japanese people refer to a green light as "青信号 (blue light)," though, we look it's green.
• Also, Japanese people refer to a green light as "青信号" (blue light), though, we see it as green.

• It is said that the reason is that we represented all colors from green to blue using only the word "blue," or we thought the contrast of red is blue.
• It is said that the reason is that we represented all colors from green to blue using only the word "blue," or we think the contrast of red is blue.

  The color red's contrast is actually green.

面白いです。I hear it is slightly blue so green-red colorblind people can see the difference.