When the fog is relatively diffused and thin enough to allow light to pass through, the tiny (less than 0.1mm in diameter) water droplets that make up fog, refract, reflect, and to a minor extent, diffract sunlight or moonlight. White tends to be dominant but, depending on the droplet size and light intensity, diffused colors can be seen on the periphery of the bands. It is commonly called a fog bow, but is sometimes referred to as a cloudbow, mistbow, or white rainbow.