As most readers will know, Munsell’s colour system organizes colour along three dimensions: hue (or what we think of as “colour”- red, green, blue), chroma (how saturated or desaturated a colour is) and value (lightness versus darkness). Munsell first published his “Colour Notation” in 1905, but it turns out that the basic idea of three-way colour dimensionality could have a very long, lost history.
According to an article published last year in New Scientist, Robert Grosseteste was a 13th century Oxford theology professor who took a keen and highly intelligent interest in just about everything. In 1225 Bishop Grosseteste wrote 400 words in Latin concerning colour theory, suggesting that colour is a property of the action of light. He also discussed it in terms of three scales: “clara to obscura”, “multa to pauca”, and “purum to impurum”, which translates into clear/dark, much/little, and pure/impure.
We can’t be sure exactly how this maps onto our modern Munsell ideas about hue, chroma and value (he may have had different concepts in mind), but it is intriguing that Grosseteste was thinking of colour in terms of three variable properties all those centuries ago.
He packed a lot into his brief thesis. It seems that Bishop Grosseteste also had an idea about colour combining which is very close to a modern understanding (the article isn’t clear about just what is meant by this), but someone back in the day got confused by Grosseteste’s use of the newly imported Arabic numerals (he was an early adopter!) and transcribed them as the Roman ones everyone was used to, so his idea was misunderstood for a long time on grounds that his reckoning was wrong. 800 years in fact, until the error was spotted and fixed. In other words, his brilliance went under-appreciated because of a typo!
We’ll never know which of the 12 Tones Bishop Grosseteste was, but it is fun to imagine him staring at stained glass and thinking about colour. He looks rather springy in his window portrait and decidedly cooler in the manuscript version …