What causes rainbow colors in clouds? [1]

Earthsky.org- 5/28/13, Deborah Byrd

Sky watchers on occasion report seeing colors in the clouds, and sometimes our friends send photos of these rainbow colors in clouds. You’ll find some examples in this post. These colorful clouds are called iridescent clouds, and the phenomenon is called cloud iridescence or irisation. The term comes from Iris, the Greek personification of the rainbow. Click inside for some amazing photos and info about iridescent clouds.

Link: Earthsky.org [2]