[lewispollard]

> it doesn’t actually matter what convention they pick, so long as everyone agrees on it and sticks to it.

That would be a good point, if that actually happened, but Japanese traffic lights have a mixture of green for go and blue for go (with most of them being green).

[jamseason]

The Japanese specification for the color of traffic lights is certainly written in Japanese. If the specification says the light should have color "ao", then either blue or green or something in between that matches it is OK.

That the color region that word encompasses doesn't match that of the English words "green" doesn't really matter, and is not particularly mysterious.

[wlonkly]

The article talks about the specification and it's more... specific than that:

> “In 1973, the government mandated through a cabinet order that traffic lights use the bluest shade of green possible—still technically green, but noticeably blue enough to justifiably continue using the ao nomenclature,” Allan Richarz writes for Atlas Obscura.

[MichaelZuo]

So there was an intentional decision to adjust the lights to their conceptual preferences. Assuming someone can source this 1973 cabinet order.

[skhr0680]

Can you tell me the location of an actual blue traffic light in Japan?

[roer]

I went ahead and geoguessr'd one of the images of a "blue" traffic light, and came to the following: https://maps.app.goo.gl/EjYmH34YC19y3fVt9

There is another one to the right as well. They look very blue when turned off, but cyan/green when turned on.

[skhr0680]

That color is common in incandescent green traffic lights around the world, not only in Japan. The idea was to use a blue-green lens to make a mostly green light when paired with a yellow lightbulb

[deadbeeves]

The daylight and the contrast with the trees don't help, either.