MICHEL PASTOUREAU  I think that I started working on colours because the topic simply didn’t exist when I was a student. But initially, I probably became interested in colours because I come from a family with a lot of painters and a lot of paintings. Three of my uncles were painters, and my father also had a lot of artist friends, so I spent a lot of time hanging out in artist studios in Paris. Since I was a little child, I have had the habit of looking at paintings. I was also taken to museums from very early on, and instead of getting bored, I really enjoyed it. I always grew up with painting.

MP  It definitely wouldn’t be possible today, either in the hard sciences or in the social sciences. Even though everyone intellectually acknowledges how good it is to work at the crossroads of different disciplines, the university requires specific tags. If you want to have a career, you need to be highly specialised. In my own case, I was trained as a historian, and not as an art historian, but I was also interested in images and colours. In addition, I also have a background in Latin philology. All of this enabled me to approach colours across different registers, whether in terms of vocabulary, or the production of pigments and colorants, or the history of clothing, science and art. I was interested in all of that, which is why my work cross-references information from all sorts of sources. This would be a lot more difficult today. My own students certainly wouldn’t be able to do what I have done. This becomes very clear when you work in a library, because they now have specialised rooms. When I was a student, large libraries would have books on philology, chemistry, or art history all in the same room. This would be difficult today, as libraries have become like department stores, with their own separate sections.

MP  I don’t think so. To my mind, colour is very cultural. There are no universal truths. Some practices can often be similar, but they always have sharp differences in terms of what the clothes and the codes mean, or in the hierarchies and perceptions of colour. We often struggle a lot when attempting to simply translate the names of colours into other languages. Even among the European languages which are closely related, the terms for colours are never completely synonymous. If I say ‘bleu’ in French, it sounds liquid. But if I say ‘blue’ in English, it is much more liquid. There is something about sound that gets lost in translation, and colours are therefore not perceived in the same way by different European ears.

MP  Indeed, that was the guiding principle of the history of blue in Europe, which is why I started off with that colour: it was fairly easy to trace its history. The Greeks and the Romans weren’t very keen on blue, and today it has become the favourite colour of Europeans. This change happened slowly over several stages, and there are quite a few documents that attest to this. But why did such a change occur? That is a little more difficult. There were many causes.

MP  That is right. As far as one can generalise, blue became the favourite colour of Europeans around the late 18th century, and it hasn’t changed to this day. Since the first opinion polls and statistics on this in the early 19th century, surveys have always delivered the same results. This is very interesting for a historian, because none of the changes in society, or the invention of new technologies, lights, or materials, have changed the answer to the question: what is your favourite colour? For 150 years, blue has come first, ahead of green, red, black, white, and then yellow. It is also interesting that these results are the same for men and for women. There is very little difference.