The sun is less bright at morning and evening as compared to at noon although its distance from the observer is almost the same. Why?
In morning and evening the light rays of Sun falls obliquely on the surface of the Earth. Thus, brightness and the luminosity of light rays from sun in morning and evening is less as compared to the noon. The beam of light appears orange because of the less luminosity.
In noon time, the beam of sunlight directly falls on the surface of the Earth. Thus, the brightness and the luminosity of the sun light is more. Due to this the beam of sun is yellow in colour.