Explain in brief why red lights are used as warning signals at road crossing?
Kindly refer to the link given below for an answer to a similar query :
https://www.meritnation.com/ask-answer/question/why-red-colour-is-used-as-danger-colour/human-eye-and-colourful-world/471286
https://www.meritnation.com/ask-answer/question/why-red-colour-is-used-as-danger-colour/human-eye-and-colourful-world/471286