The colors of the rainbow were brighter than they appear in this photo. I don't believe I've ever before seen a cloud bearing rainbow hues in quite this way. The cloud moved southward across the sky rather quickly, spreading out as it moved. But the colors never left it. As you can see in the photo, there were other clouds in the predominantly clear sky, all of them normal "white" ones. I suppose there must have been just the right form of moisture in or near this one cloud formation to create the rainbow.
Appropriately, first thing yesterday morning on the BBC's "World" radio program, and again in the afternoon on "The World" from WGBH Boston, I heard about the Cloud Appreciation Society in the United Kingdom. So I attempted to join up! Soon I hope I'll have a spiffy certificate to show for it.
I do enjoy and greatly appreciate clouds and their intriguing and ever-changing shapes and colors. At the same time, in light of the loss of the Air France Airbus jet over the Atlantic yesterday, I feel moved to remember that clouds are not just "pretty things". Sadly, some clouds carry murderous weather conditions.