Colored Copy
Although the formation of any rainbow involves both reflection and refraction (bending) of light, double rainbows are formed when light reflects twice inside the waterdrop, causing the second rainbow to be seen in reverse direction from the primary (brightest) rainbow. In this photograph, you can see the spectrum of the upper rainbow is in the opposite direction from the lower rainbow (the blue-violet colors are at the bottom of the lower rainbow and at the top of the upper one).
