Question

Why does the blue colour predominate in a clear sky?

Answer 1

The wavelength of blue light is very less...

And therefore it scatters the most..

Which is why it is predominant in the sky.......

Answer 2

The atmosphere on earth consists of various gases, and gases consist of atoms and molecules.The sun, being an extremely huge and bright source of light, showers a wide range of colours of light which have distinguished wavelengths from each other.Now, due to the presence of the atoms and molecules in the atmosphere, the light's wavelengths are scattered. On scattering, the blue wavelength dominates all the others.This scattering is the most basic reason for why the sky is blue.