Question

why danger colour appears always red​

Answer 1

The primary reason why the color red is used for danger signals is that red light is scattered the least by air molecules. The effect of scattering is inversely related to the fourth power of the wavelength of a color. ... So red light is able to travel the longest distance through fog, rain,.

Answer 2

because red colour has longer wavelength and hence the scattering of light is less and thus a person standing at far distance can also see that there is danger ahead....