The Portland Colour Chart

The Portland Colour Chart

Colours and Materials

The swatches have all been painted on old corks cut in half. This was obviously a cheap and easy way of making a simple but effective prop for the colours. The palette hues are mainly blue/green/yellow with only a small portion dedicated to warmer colour (mainly earth colours). Their value or tonal range is muted with low chroma values (pastels). Pigment identification has revealed a huge range of colours used, making it difficult to date precisely. Right is a description of the most interesting and unusual pigments used.


Indian Yellow- A pigment originally made in rural India. It was made from the dried urine of cows strictly fed on a diet of mango leaves. Its production was prohibited in 1908 as the cows became completely emaciated.

Mummy- A pigment used widely in 17th and 18th Century. Egyptian Mummies when ground produced a brown pigment with good transparency. One Egyptian mummy gave sufficient amounts to satisfy the demands of one colourman’s customers for seven years.


It is difficult to be precise on exactly the colour Library’s purpose. Without doubt it was a chart plotting and naming the colours on Portland. Whether it was for scientific or artistic purposes is unclear. However, due to the many layers of paint on each of the samples, it seems it was a working library, each swatch being painted over many times in the search of the correct and perhaps exact match.

The numbers under the swatches are not in numerical order and seem apparently random. However, they could have related to a map or chart identifying the position of where the colours were matched. The index found with the Library reveals only three colour names, No 34, Portlandia Screw Buff (after a fossil found on the isle, Aptyxiella Portlandica) and No. 42 Balaclava Blue (a bay on the north east side of the isle) and No. 21 Blacknor (an area on the west side with steep cliffs and Blacknor fort at the top).

This is on display at the Portland Museum –