Step-by-step explanation:
Refraction is the phenomenon which occurs when there is change in the direction of the light while traveling from one medium to the another medium.
Our atmosphere consists of the rarer medium and denser medium. The light gets refracted from when it travels from the sun. Blue, indigo and violet are strongly bent than any other colors. The blue has a shorter wavelength. Blue light is scattered more by the tiny air molecules than any other colors. Therefore, the sky appear blue in noon.