It is profound how red is used for stop signs and lights, and all the signals mentioned in the article.
I have not realized It is the first color we stop seeing at dawn.
Fun Facts
Red has the lowest wavelength that we perceive and violet being the highest.
Inferred while to low of a wavelength to be seen, can be used to determine how much heat energy an object is emitting.
-3D
Great additions, thanks for it!