Blue means go???

I'm waiting at an intersection in Tokyo a couple years ago, speaking with a friend. She looks up, and says "Oh, it's blue, let's go!" referring to the pedestrian traffic light. "Don't you mean green?" I say as we hurry to cross the street, double checking to confirm that I haven't missed a major difference in Japanese traffic signals. The light is in fact the exact same shade of green I'd expect from back home in the U.S. "No, no, street lights are blue; red, yellow, blue." From this exchange, I wondered, do Japanese people have some unique sensory perception where in specific contexts only, they perceive the world in a different color than everyone else?

Well, the reality is, in the Japanese language, traffic lights are 赤 (red), 黄 (yellow), 青 (blue) while their actual physical colors remain rather consistent with international standards (in English: red, yellow, and green). This especially came as a surprise to me because I knew that there existed a word for green in Japanese, 緑 (green).

As it turns out, there are a number of languages around the world that do not distinguish between green and blue. To speakers of these languages, you would use the same word to describe the color of a leaf and the color of the sky, or else you would qualify it as "leaf blue/green" or "sky blue/green". Linguists use the attractive word "grue" to describe this unspecified blue/green color designation.

For Japan, this very phenomenon was the case, only having the word 青 (read "ao") which today is used effectively as blue. Prior to World War II, this word was used to describe everything we would regard in the realm of blue and green, and it was not until the occupation following the war that linguistic distinguishment between green and blue arose. It is from this era that the word 緑 (read "midori") arose as more than just a shade of "ao" and instead came to distinguish green colors as different from blue ones....for the most part.

There remain a few culturally lasting exceptions where the traditional term "ao" is still used to describe what would technically/perceptually fall under the category of green. These exceptions include traffic signals, grass, leaves, as well as a few others. So, when a Japanese person says that a traffic light is "red, yellow, and blue", they are literally translating a culturally lingering linguistic vestige, not indicating a unique sensory perception.

For more information regarding linguistic distinctions of color, as well as descriptions of various languages that have their own versions of "grue", click here.