Why Japan Has Blue Traffic Lights Instead of Green

Re:Why Japan Has Blue Traffic Lights Instead of Green by BurningFrog on Monday October 23, 2023 @11:36AM (#37987226)

The "fuzzy clouds" argument is both true and important.

But there also are some basic truths about human vision.

We only see three "simplified" different colors, red, blue and green, and other nuances are interpolations our brains make. There is infinitely more frequency information in light that we just don't pick up.

So I would expect that the primary colors red/blue/green, which are grounded in human physiology, were universally recognized across languages. To the extent they're not, that's confusing.

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Re:Why Japan Has Blue Traffic Lights Instead of Green by Retric on Monday October 23, 2023 @11:53AM (#37987483)

The color receptors in your eyes don’t actually correspond with red, blue, and green with the same wavelengths being able to trigger multiple receptors. On top of this your retina absorbs more blue light as you age.

https://en.wikipedia.org/wiki/Cone_cell#/media/File:Cone-fun...

So, defining the separation between Red, Blue, and Green is really fairly arbitrary.

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