I love Fry and Cleese, and I think they are both well-read and well-informed. They might have done their own inquiry about pink and blue, but it's more likely they read or heard about it from someone who did the research. It could be me, since I've been writing articles and doing interviews about pink and blue for 30 years. It could also be British historian Clare Rose, who has done parallel work in the UK, or some uncredited media intern.
Oh, for a real time machine! A researcher could publish the results of years of research at the moment of the first discovery!