Rainbows 

Rainbows are optical and meteorological phenomena that cause a spectrum of light to appear in the sky when the sun shines onto droplets of moisture in the Earth's atmosphere. They take the form of a multicolored arc, with red on the outer part of the arch and violet on the inner section of the arch. More rarely, a secondary rainbow is seen, which is a second, fainter arc, outside the primary arc, with colors in the opposite order. That is with violet on the outside and red on the inside. (Wikipedia)

Find our more about rainbows by following the links below.