Question

Why does the bluish colour predominate in a clear sky?

Answer 1

The scattering of blue component of the white sunlight by air molecules present in the atmosphere causes the blue colour of the sky.The sunlight Is made up of seven coloured lights mixed together. When sunlight passes through the atmosphere, longer wavelength lights present in it do not get scattered and they pass straight but blue is of shorter wavelength so it scattered all around the sky . So wherever you see some of blue light enters our eyes.

Answer 2

Hey !!

At the time of sunrise or sunset, the sun is just above the horizon; sunlight travels a longer distance through the atmospheric particles. The amount of scattering is inversely proportional to the fourth power of the wavelength.

             I ∝ 1 / λ⁴

Since, λb << λr. Hence, the bluish colour predominates in the clear sky.

Good luck !!