Last Saturday while anchored in Port Ludlow, The sky put on a show for us. Apparently the relative humidity way up there, where the transcontinental jets fly, was 100% because their contrails didn't evaporate - they just hung around getting bigger and bigger, being blown into the most interesting shapes.
But the most amazing thing was when the sun hit those clouds just right, and this happened:
I know that this did not photograph particularly well. And what no photograph could possibly capture was the sparkling iridescence that the colors showed. I guess you had to be there. But since you weren't, I am trying to share it with you.
At the altitude where these contrail clouds resided, this was surely ice. One of the names Wikipedia gives for this phenomenon is "fire rainbow"; I can attest to the appropriateness of that name.