Fire Rainbows: A Rare Cloud Phenomenon By Kaushik Sunday, May 19, 2013 Nature, Photography, Science 27 comments “Fire Rainbows” are neither fire, nor rainbows, but are so called because of their brilliant pastel colors and flame like appearance. Technically they are known as circumhorizontal arc - an ice halo formed by hexagonal, plate-shaped ice crystals in high level cir..