Actually, I believe Alexander Gerard only designed the interiors for Braniff when the "jellybean" look first appeared in the mid-60s. I'm sure it was Mary Wells (and the advertising agency she worked for) who was responsible for coming up with the Flying Colors idea. Of course, as we know, Mary Wells ultimately had her own ad agency, Wells Rich Greene, which was very successful but eventually went out of business a few years ago. And, don't forget that Mary Wells also wound up marrying Braniff's CEO, Harding Lawrence.
In any event, I loved the ultra colors, especially the brown and dark green.