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Why does red mean "stop" and green "go"? Answered

Why did they use red and green for stop lights ?


Red is a colour almost universally connected to danger - Possibly because of your blood being red. Green is almost universally regarded as safe - Perhaps because we see green things as food and so not any danger. Amber (yellow) is not as universal for caution and was chosen because of the good contrast with green and red. So Red = STOP - Danger Green = Go - Safe

Red is a color that people normally think of as DANGER! or STOP! Green is more or a subtle and safe color.

That's the way the inventor set it up in the beginning.