Question

Colour of the sun at sunrise and sunset

Answer 1

during sunrise or sunset the colour of sun appears red because at that time sun is at the horizon. so, the wavelength of red become longer and spread or the blue colour can't spread. so sun appears red.

Answer 2

At the time of sunrise and sunset , when the sun is near the horizon ,the sunlight has to travel the greatest distance through atmosphere to reach us . During this long jounery of sunlight ,most of the shoter wavelength blue colour present in it is scatteres out and away from our line of sight . So,the light reaching  us driectly from the rising sun or setting sun consists mainly of longer wavelength red colour due to which sun appears red