These -- or some of them -- can appear in human shape. I was wondering whether to make them colorful (if not perhaps so brilliant) the same way. Some of the colorful ones, my muse was seeing as less -- saturated in the human form. (There were also ones that were colorless. They can stay that way.)
Then I remembered that at one point, the characters are surprised to see one of the human shapes wink out, since that was the first actual difference from human. You could be less than vivid, but not actually colorless.
I shall have to ponder. Certainly there's one whose lack of color in human form, as presented by the muse, is anomalous, but perhaps that one is odd for a specific reason.