You must have enjoyed viewing red sky during sunrise and sunset many a time. But what makes the sky appear red during these two phases of the day is the question that amazes many a people. Usually, the light of the sun comprises seven different colors, like blue, violet, red, etc., throughout the day, but out of these seven colors, the red color has the longest wavelength.
Considering the fact that sun rays have to travel a larger part of the atmosphere during the sunrise and sunset, due to their close proximity to the horizon, in comparison to other times of the day, the red light/color, which is least scattered than other colors, catches our eyes. While the remaining colors/lights disappear in the sky before they reach your eyes.