Who decided red means "stop" and green means "go"?

What a normal person sees vs what a color-blind would see

Who decided, back in the mists of time, that red was the color for "stop" and green the color for "go"? The commonest form of color blindness makes the colors totally useless. A warning sign that is near-invisible to a significant portion of the population strikes me as a bad idea.

- Barbara T., Los Angeles

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