My association is immediately to
Rainbow Rowell. She was originally a newspaper columnist for the Omaha World Herald, the paper my column on names appears in, and has now gone on to be a quite successful writer of "young adult" novels. Having read her newspaper columns over the years, I think my impression of someone named
Rainbow is of someone a great deal more intelligent, thoughtful, and serious than the one I would have had before I became aware of Ms. Rowell. By the way, I know from a column she wrote years ago that
Rainbow is the name her parents gave her -- it's not just a pen name.
https://www.rainbowrowell.com/
https://en.wikipedia.org/wiki/Rainbow_Rowell