If you search the Internet for the Electromagnetic Spectrum. Some pictures clearly show the position of the colors that are also often seen in a rainbow. Imagine cutting a horizontal slice from a rainbow and placing it in a straight line. From left to right the human eye can see violet, indigo, blue, green, yellow, orange, and red. The colors run into each other without clear demarcations between each one. There is a band of blue light on the spectrum, which has one of the shortest and highest-energy wave lengths. Blue light waves are everywhere. Did you ever wonder the reason the sky looks blue? When the sun’s rays travel through the atmosphere, the high-energy blue waves crash into the air molecules, scattering blue light everywhere. Blue light waves from the sun helps you feel alert, be in a pleasant mood, strengthen your immune system, and regulate your circadian rhythm. Whenever you are out of doors, you can be exposed to blue light wherever the sun’s rays can reach you.