What is the difference in colours of the Sun observed during sunrise/sunset and noon? Give explanation for each.
At noon the sun appears white because the light from the sun is directly overhead us. The light travels relatively shorter distance during the noon. Scattering of light is reduced as the distance is reduced.
Amount of scattering is inversely proportional to fourth power of wavelength.
So, the sun appears white as only a little of the blue and violet colours are scattered.
The sun looks reddish during sunrise/sunset, because at this stage, rays from the sun have to travel a much larger part of atmosphere. As the distance increases in this case, scattering of light increases. So, red colour having largest wavelength is scattered the least.