Meteorology

Sunlight contains all of the colors of our visible spectrum.  These colors combined together appear white. 

Red light has the longest wavelength and, therefore, the least amount of energy in the visible spectrum. Wavelength decreases and energy increases as you move from red to violet light across the spectrum in the following order: red, orange, yellow, green, blue, and violet.

The sky is blue because of the scaterring of the wavelength passing thru the molecules of the air. The scattering caused by these tiny air molecules known as Rayleigh scattering increases as the wavelength of light decreases.

Violet and blue light have the shortest wavelengths and red light has the longest. Therefore, blue light is scattered more than red light and the sky appears blue during the day.