Rainbows are colorful bands of light that are formed when water particles in the air reflect sunlight. As sunlight enters the drops and droplets, the different wavelengths of colors that compose sunlight are refracted at different wavelengths to produce a spectrum of color. To see a rainbow, you must be standing with the Sun behind you and the raindrops in front of you. The Sun needs to be less than 42° above the horizon to obtain the correct angle so that the light waves are properly reflected. The light is refracted as it enters a raindrop, reflects off the inside of the back of the raindrop, and is refracted again as it leaves.