It's a style frame inspired by the book Exercise in Style by Raymond Queneau, first published in French in 1947. In Queneau’s book, the same two-paragraph passage (Notation) is written in 99 different ways.
This style frame is based on one of them, which is The Rainbow.
One day I happened to be on the platform of a violet bus. There was a rather ridiculous young man on it--indigo neck, cord round his hat. All of a sudden, he started to remonstrate with a blue man. He charged him in particular, in a green voice, with jostling him every time anybody got off. Having said this, he rushed headlong towards a yellow seat and sat down on it. Two hours later I saw him in front of an orange-colored station. He was with a friend who was advising him to have another button put on his red overcoat.