Where clouds are made up of especially tiny ice crystals or water droplets, they can cause light to be diffracted, creating this rainbow-like effect in the clouds. I saw one to the left of the sun as I was driving up interstate 95 from the capital beltway and then when I got onto Maryland 200 (the Inter-county Connector) I saw this on to the right of the sun. I was able to pull over and take a couple pictures of it before it faded away. I love clouds and take pictures of them fairly often but don’t figure most people will be as interested as I am, so only post them here when they are involved in sunsets or particularly unusual (like the Fallstreak hole I photographed in November, 2013). This isn’t nearly as rare as that, but I still like it when I see it.