I know why the colors of a...

The first definition of a rainbow (by Descartes) was based on tracing the path of a light ray falling on a transparent sphere. If the Sun is at the horizon, the rainbow is an arc of 180 degrees, but it cannot appear if the Sun is high in the sky. Red, orange, yellow, green, blue, indigo, and violet (ROYGBIV) are the colors of a rainbow, but these are not necessarily the sequence of colors an observer sees. Since the color sequence of a rainbow is the result of refraction, the color order depends on the viewer’s angle of perception. As for the end of a rainbow, it seems always to elude us. However, here at The Old Farmer’s Almanac, we firmly believe that there’s a pot of gold waiting for the person lucky enough to find a rainbow’s end.