In the aftermath of Isaac Newton’s revelatory publication Opticks: or, A Treatise of the Reflexions, Refractions, Inflexions and Colours of Light (1704), a new preoccupation with the nature, order and shape of colour began to take seed. In the decades following Newton’s publication, scientists squinted through prisms in darkened rooms across Europe – seeking to replicate Newton’s various prismatic experiments, and to tease out some order and meaning from the colours they saw. As a consequence, the eighteenth and early nineteenth centuries witnessed a glut of colour books, written to corroborate, contradict or continue Newton’s seminal treatise on light and colour. Their authors explored various visual methods of representing the colours – from numbered lists with lines of coloured swatches, to colour circles, triangles, diamonds, pyramids and spheres.
Newton’s own treatise includes one of the first circular representations of colour. In his famous experiment, Newton intersected a white ray of sunlight with a triangular prism, and watched the coloured spectrum reveal itself on a white wall. Equating the vibration of coloured light rays with the notes of the music scale, Newton split the spectrum in seven – into red, orange, yellow, green, blue, indigo and violet. In his black-and-white colour wheel, published in Opticks, Newton looped his chromatic ROYGBIV scale around to form a circle. Since then, the colour circle (or wheel) has become a familiar visual tool for representing colour. For example, entomologist Moses Harris designed three colours wheels – two to illustrate his influential publication The Natural System of Colours (1766), and one to display the most commonly occurring entomological colours in his Exposition of English Insects (1782).
While many eighteenth-century theorists chose the circle as a means to graphically make sense of colour, others took a more angular approach. Perhaps the most famous of these is Tobias Mayer’s colour pyramid (1758). Mayer’s colour diagram was first put into print in 1775, when the Göttinger physicist Georg Christoph Lichtenberg issued a collection of Mayer’s unpublished works, in which the colour pyramid appeared, depicted in multi-level, three-dimensional form. An adapted, three-dimensional version was also published by Johann Heinrich Lambert, in Beschreibung einer mit dem Calauschen Wachse ausgemalten Farbenpyramide (1772). Sixty years later, another example of triangular colour appeared in David Ramsay Hay’s A Nomenclature of Colours, Hues, Tints, and Shades, Applicable to the Arts and Natural Sciences (1846). Hay’s nomenclature, like Harris’s entomological circle, is concerned with the naming of colour, as well as the visual harmonies and dissonances between individual hues.
In 1809, naturalist James Sowerby published A New Elucidation of Colours, Original, Prismatic and Material, in which he expressed his dissatisfaction with existing colour systems. In particular, he was concerned with the impermanence of pigment. To his mind, painted charts were unsuitable as a means to represent colour, as they often faded and discoloured, polluted by time and exposure to light. Instead, he set out to develop a standard, universal and permanent method of identifying colours, by peering at different thicknesses of black line through a prism. Ironically, in order to illustrate his system, Sowerby included a painted chart – a geometric creation of interlocking diamonds.
Perhaps the most straightforward method of representing colour is though the list, or table, like the zoological hues of Walter Charleton, published in 1677. Lists and tables of colours were particularly useful for artists and dyers, and for naturalists, who were concerned with identifying specific natural hues. For example, in 1769 the botanist Jacob Christian Schäffer published a slim booklet containing his proposed system for naming and identifying the colours of the natural world. He began filling in a tabular chart for the reds, passing it on to his readers to complete. A few years later, in 1814, the botanical illustrator Patrick Syme published Werner’s Nomenclature of Colours – a book of colour charts that went some way to completing Schäffer’s proposal. A second edition of Syme’s book was published in 1821. Artists also produced similar charts for depicting the colours of landscapes and natural subjects, including George Brookshaw’s A New Treatise on Flower Painting, or Every Lady Her Own Drawing Master (1816).