This is horribly amateurish reporting on Gibson's part. It's an old story and he still can't get his facts straight.
I think you two missed the point. O'Reilly, as often is the case, got the story wrong, and Plano jumped on that to deny they had ever done anything wrong.
Gibson is pointing out that in fact they DID ban green/red icing on cupcakes, and napkins and plates. He has the letter sent to the parents from the school which tells them what colors they can and can't use, and WHY. The letter apparently says it is because it is a "holiday" party, and that green and red are christmas colors.
Gibson is trying to point out that he covered this in his BOOK, which was published already, and that Plano is wrong to deny that they banned colors simply because they didn't ban colors on CLOTHING.
Gibson never said they banned clothing colors, that was an O'Reillyism.