In Japan, some traffic lights indicate “go” with a blueish hue, rather than the standard green. It’s all due to a quirk of language:

Traditionally, the Japanese language used the same word for blue and green, “ao.” So the bureaucrats of Japan had a predicament. The word for green is now “midori,” but with the Japanese people associating the word for blue with a distinctly green traffic light, how were they supposed to refer to it officially? And simply changing the light to blue instead of green went against a major worldwide push to standardize traffic signals. So in the early 1970s, Japan decided on a blue-green color sometimes known as “grue” or “bleen,” meaning it’s technically both. While today only some lights combine the colors, and others are clearly green, all of them are still “ao.”

The words “grue” and “bleen” both make me chuckle.