Fogbows are optical phenomena in the atmosphere. They are quite similar to rainbows, but appear in fog. Like rainbows, fogbows can be seen when sunlight is refracted by water droplets and splitted into its spectral colors. But, because water droplets in fog are very small in size compared to rain drops, the refracted spectral colors are faded with very weak colors. This might be the reason that they are sometimes also called "white rainbows".