Coded Colours
Botanical Histories of Colour Standardization
By Elaine Ayers
Describing a “new” orchid found growing deep in the Guatemalan rainforests in 1840, British collector George Ure Skinner tried to put the dappled flower’s colouring into words. Its petals, he wrote, were a “delicate waxy white slightly tinged purple, while in many instances the petals are of the most brilliant rose.” [1] Without access to his paints or coloured pencils, the collector was forced to translate the flower’s appearance and value into words—words that extended beyond the realm of botany and into the future of Britain’s imperial interest in these distant rainforests, into nineteenth-century ideals of beauty, always contrasted with the ungraspable exotic “other.”
The story of botanical colour is one rife with inconsistencies and halting starts and stops, a tug-of-war between permanence and ephemerality, between materiality and decay. Centuries of scientific and artistic overlappings rooted in the colonial enterprise of collecting expeditions produced the neatly standardized Munsell Colour Charts used by naturalists working in the field today, each seemingly innocuous numbered colour obscuring the racial, gendered, and economic histories involved in their making.
![Image 1 | Maxillaria skinneri, del. George Ure Skinner, in George Ure Skinner to William Jackson Hooker, 26 October 1840 [Guatemala]. Royal Botanic Gardens, Kew, Library & Archives. Directors’ Correspondence vol. 68, f. 134b](https://images.squarespace-cdn.com/content/v1/5671ee0a0ab3774b3457b1ad/1587151019503-7BFBM0TTT8V83ZJL3BPZ/The+Site+Magazine+Volume+40.2+Collect+Coded+Colours+Elaine+Ayers)
Image 1 | Maxillaria skinneri, del. George Ure Skinner, in George Ure Skinner to William Jackson Hooker, 26 October 1840 [Guatemala]. Royal Botanic Gardens, Kew, Library & Archives. Directors’ Correspondence vol. 68, f. 134b
Skinner’s interest in this orchid, a fine specimen of Maxillaria skinneri, arose from this very context: his own mission combining expert botanical knowledge with very real economic concerns amidst a need for hands-on artistic training. By the mid-nineteenth century, ever-growing numbers of colonial collectors were working in the rainforests of Central America in search of rarer, more curious plants, hoping to secure funding and, perhaps, a discovery that would bring lasting scientific fame. In this increasingly competitive field, Skinner had a distinct eye for what both commercial and botanical buyers desired in an orchid. Reproducibility, fragrance, and novelty, certainly, but also striking, evocative colour in line with the “fashions” that governed both nurseries and royal scientific institutions—fashions that were largely created and controlled by the wealthy women who bought plants, illustrated them, and financed what, by the turn of the nineteenth century, had been termed a “feminine” field of study.
If Skinner provided his patrons with an orchid that failed to match his initial description, the fragile two-way trust in observational accuracy governing long-distance collecting broke. Inaccurate descriptions of specimens later questioned by other competitive collectors working in situ or, worse, living bulbs precariously—and expensively—transported to Europe that bloomed into a dingy brown or malodorous flower breached this trust. Too many breaches and the entire imperial botanical infrastructure threatened to collapse. The stakes of keeping one’s own head while upholding the inner workings of an entire field were profound.
The problem of communicating “accurate” floral colour across time and space, though, was a complex one, earning new terminology and attempted technological interventions as pigments, paper, and colour theory itself changed over the course of the eighteenth and nineteenth centuries. Half of the challenge of botanical illustration was material: naturalists had little access to reliable paints and colouring tools in the field, they usually worked quickly across a wide variety of specimens, and the colours they did successfully put to paper faded, bled, and rotted in tropical climates and on long oceanic journeys.
Image 3/ “Crimson, 8,” Mary Gartside, An Essay on a New Theory of Colours
The other half of the problem was translational. How could a naturalist describe the particular pinkness of an orchid to illustrators, botanists, or buyers back home, most of whom would never see a living specimen? How could a collector be sure that what they were seeing was “accurate” at all? The answer, at least initially, lay in colour standardization—named and tinted, fixed on paper or under glass, numbered and measured. Colour, in all of its affective ephemerality, was subject to codification along with the plants it described, which were neatly transcribed in binomial nomenclature. Whether artists could achieve this desired standardization was far more complicated.
The idea of standardized colour production and mixing far predated the era of eighteenth-century global exploration associated with botanical taxonomic standardization—instructions written for workshops of assistants by alchemists and artists describing specific reds and golds made from ground minerals creep through the margins of fifteenth-century manuscripts and across the pages of Leonardo da Vinci’s notebooks. The first colour chart occupied a foldout plate of the 1687 Philosophical Transactions, described in three pages of text by chemist and artist Richard Waller. [2] Noting that “a Standard of Colours being yet a thing wanting in Philosophy,” Waller listed his pigment mixtures by weight, number, and source, attributing “Blood-red,” No. 12, to the rich gum of Sanguis Draconis, a South Asian tree described in the wildly popular Hortus Malabaricus. [3]
Most historians, though, attribute the standardized colour chart to Ferdinand Bauer, a Czech artist employed on some of the most famous expeditions of the eighteenth century—first working alongside John Sibthorp illustrating the naturalia of the Mediterranean in ten massive volumes and later hired by Joseph Banks to delineate the late eighteenth-century journey of the Investigator to Australia and the South Pacific. Faced with thousands of specimens to illustrate while constantly moving (and working aboard an unsteady ship), Bauer found himself unable to even partially colour his drawings, lamenting over his inability to describe “accurate” colours to engravers back home, committing his “discoveries” to science as well as art. [4] The artist’s solution was a “paint-by-numbers” chart whose taxonomy of precisely calibrated colours was even more striking than the species it was used to depict.
By dividing numbered shades of pigments into small rectangular strips, Bauer’s method allowed naturalists and illustrators to leave their pencil or ink drawings uncoloured while working in the field, prioritizing speed and volume over completion. On site, they could match their specimen to a numbered colour sample, pencil in its corresponding shade, and leave painters to match each section from the safety of printshops and parlours back home. Bauer and his collaborators relied heavily on the chart, gradually expanding it to include more shades while employing workshops of colourists in producing some of the most lavish and expensive floral tomes decades after returning to the British and European scientific societies and gardens that funded their expeditions.
Naturalists in a variety of fields expanded on these paint-by-number charts, adding species-specific (oftentimes poetic) names to each colour while fixing their samples against external objects of comparison. Adapting a long-forgotten mineralogical colour chart produced by German fossil-hunter Abraham Gottlob Werner in 1774 (whose rocky subjects were far more stable than quickly fading plants or wily animals), Scottish artist Patrick Syme translated, edited, and published the now-famous Werner’s Nomenclature of Colours, a slim guidebook of hues carefully numbered and matched to a corresponding plant, animal, and mineral. [5] Adapting the original dry, insular text to a handbook designed for a new class of Romantic readers enamored with travel and the natural world alike, Werner’s “No. 27, Brownish Purple Red” became “Flower of Deadly Nightshade” and “Red Antimony Ore,” while “No. 28, Chocolate Red” translated to “Breast of a Bird of Paradise” and “Brown Disc of Common Marigold.” [6]
Image 4/ Tab. 5, James Sowerby, A New Elucidation of Colours, Original, Prismatic, and Material
So why were these nomenclatural and numeric colour charts largely unsuccessful, unused by all but a few artists working on well-funded projects with fully stocked libraries? At stake was something shared by the very same flora these naturalists struggled to preserve on long expeditions—the pigments themselves degraded over time. Subjected to the same tempestuous environmental conditions as their floral subjects, colour charts bled and bleached in hot, humid climates and stippled in salty sea spray, quickly rendering any notion of “standardization” worthless. Engraving Bauer’s Mediterranean plants from London, James Sowerby lamented that while artists had “long wished for some never-fading colours to fix their ideas and universalize them, coloured substances, like all sublunary things, are liable to a certain decay.” [7] While some pigments like cochineal red and indigo blue held their true hue and saturation for decades, other mixtures like Hooker’s Green and Velvet Black faded into new shades entirely, corrupted by the light that determined their perceptive existence. [8]
As Johann Wolfgang von Goethe developed his quintessentially Romantic colour wheel from his home in Germany, arguing for the inherent sensuality and morality of colour (yellow as pure and serene, blue as cold and melancholy), a “mere flower painter” working in London presented her own intervention into the largely male field, navigating between Newton’s additive, light-based mixing and her own subtractive, paint-based mixing to produce a series of colour “blots” specifically designed to describe the colours of plants. [9] Trained in watercolour, Mary Gartside presented a new theory of seeing and producing colour as sensory rather than simply material. Accepting that colour perception took place, quite literally, in the eye of the beholder, Gartside instructed her (mostly female) readers in how to manipulate pigments to create desired effects in botanical illustrations and floral arrangements.
Gartside painted eight amorphous colour blots emanating from a white centre, instructing readers to “suppose, for the sake of illustration, that each blot is a group of flowers,” specifying that they were, technically, “merely blots of colours, exhibiting the effect produced by arranging them according to the theory delivered by the foregoing pages.” [10] Rather than assigning a standardized name or number to each colour, Gartside rearranged the prismatic order of colours first presented by Newton to better suit the art of subtractive, paint-based colour mixing, emphasizing brightness, harmony, and contrast—the key sensual conditions shaping individual perception reflected onto the eye of the beholder—over a singular external hue. To this “flower painter,” material standardization was impossible (and premixed colour palettes were not to be trusted), but successful artists and naturalists could understand the effects that juxtaposition and blending had on colour perception for the viewer.
Image 5/ Tab. 6, James Sowerby, A New Elucidation of Colours, Original, Prismatic, and Material.
But inherent to this theory of colour perception was the central problem with translating colour from the field to the page, a problem transcending Bauer’s attempt at mitigating time and distance with numbers: How did a naturalist know that what they were actually seeing in situ was “accurate?” If, as many collectors noted, the monotony of the middle-green jungle or rolling ocean exhausted the eye, distance distorted colours towards blue, charts themselves degraded over time, and commercial pigments varied according to manufacturer and mixture, the idea of a universal standardizing device seemed ever-impossible, a material victim to the frailties of the eye, mind, and hand as well as climate.
In correcting for the visual fatigue of travelling through the monotony of green forests or grey oceans, artists turned to physiological developments, advanced by physicists like Thomas Young, demonstrating that humans’ experience of colour was formed by the mixing of three wavelengths within the eye itself. [11] If colour mixing was a physical rather than sensuous phenomenon, as artists like James Sowerby believed, then physical devices modelled on other optometric instruments might help standardize both material colours and viewers’ colour perception. Sowerby, highly trained in the art of botanical illustration, proposed his solution in the early nineteenth century: the “chromatometer,” a strikingly abstract set of black lines and wedges printed on a large sheet of white paper onto which a prism could be refracted, functioning “as an independent instrument (something like a barometer)” for use in the field, study, or herbarium. [12] Working within controlled light and space, botanists and artists could find a specimen or sample’s precise shade on a dissected prism, measure its placement in each segment, and match it to agreed-upon points of pigment reference.
Realistically, naturalists found Sowerby’s chromatometer difficult to use and, while lightweight and as easy to pack as a colour chart, wholly impractical for the field. The challenge of setting up a controlled system of lighting proved near impossible in the basecamps where botanists tagged their flora at night, and waiting to describe their colours until they arrived back at a centralized location meant wilted, faded, and dried specimens. While Sowerby intended his device to standardize colours “to all parts of the world, and the remotest ages,” it failed to conquer the ever-present bastions of time and place bound up in botanical labour from collection to representation. [13]
Another such optical device was presented by the British inventor and chemist George Field, who employed both light- and paint-based colour mixing in developing his “metrochrome,” a bulky box intended to render his own star-shaped colour wheels practical for relatively unskilled observers of nature. Eschewing colour nomenclature in favour of numeric precision, Field designed three-dimensional glass prisms in the shape of wedges fitted into a wooden box, each filled with coloured water. These progressed in saturation, the largest end of the wedge representing the deepest, darkest version of red, yellow, or blue—the “eruthrometer,” “xanthometer,” and “cyanometer,” respectively. Along each of these prisms ran a thin ruler allowing the observer to measure a hue’s precise value against Field’s own colour wheels. To mix these primaries infinitely, the chemist devised a case into which all three prisms could be inserted, sliding in and out on top of one another at controlled degrees; a small glass window at the top allowed the observer to see their desired mixture isolated from the influence of surrounding colours: a perfect glass colour swatch. [14]
This “swatching” of colour—a hue reduced to a contained box, named, and numerated—obscures the classificatory damage done by codifying the material and immaterial world around us. Certainly, standardization was, and is, necessary in communicating the colour of an orchid across time and space, in ensuring that artists could work from a paper-based description of a plant if not “from life.” However, attempts at standardizing colour, at assigning a neat taxonomy to something so intangible and ungraspable, has necessarily rendered certain colours, certain mixtures of colours, more valuable than others—whether classified as “Blood-Red, No. 12,” or as “Breast of a Bird of Paradise.”
Image 6/ “Chromatometer,” James Sowerby, A New Elucidation of Colours, Original, Prismatic, and Material.
Indeed, the codification of colours was, from the outset, entangled with gendered and sexualized ideas closely tied to the colonial construction of the “exotic.” Werner’s Nomenclature, which traveled widely thanks to its concise and convenient format, standardized the terminology associating pale pink and stippled, white hues—and notions of floral beauty and delicacy—to the blushing cheeks of upper-class white women shielded from the tropical sun. In developing his 1834 Ladies Botany, the book rumored to mark the final professional exclusion of women from a previously feminized botanical field, John Lindley, “father of modern orchidology” and frequent correspondent of Charles Darwin (an early user of Werner’s Nomenclature), relied on the colour guide in describing the varying “pallor” and “healthy colour” of his beloved flowers.
Separating a newly male-dominated “scientific” botany from what he considered the more feminine art of floral arrangement, illustration, and gardening, Lindley likened floral delicacy and fragility to his readers’ bodies, prizing the pinks, roses, and whites common to tropical hothouse orchids for their resemblance to that paragon of sexualized white femininity: the blush. [15] To Lindley and so many others, the brightest colours in the vegetable kingdom and the primaries of the paint-based colour spectrum—red, yellow, blue—signified, by comparison, vulgarity, sexual availability, and, later in the century, a “primitivism” associated with tropical aesthetics and unsightly modernism. [16] Numerous nineteenth-century interior and horticultural guides, building on this colour theory, instructed readers to avoid bright primary colours in designing rooms and planting beds and to harmonize complementary colours, as Gartside had suggested, to better “soothe the eye.” [17]
Nature’s vast spectrum of colours had become inextricable from the eighteenth- and nineteenth-century value systems imposed upon it. While a subtly harmonized orchid conjured images of frail, “pure” upper-class white women particularly ill-suited to tropical life, brightly coloured specimens warned of hidden, invisible poisons and conjured reports of colonial officers’ interactions and dalliances with exoticized foreign peoples. Such clandestine dangers contributed to new definitions of race, sex, and potential processes of evolution and degeneration that might emerge from colour “mixing”—from sexually transmitted diseases to the collapse of entire civilizations. [18] By the late nineteenth century, the tanned and leathered hands of a working-class woman, perhaps tinted by the pigments she mixed in a textile factory, completed the spectrum of perceived incivility, a burgeoning victim of the Social Darwinist movement based, in large part, on notions of standardization.
The rest of light- and paint-based colour theory is a history of modern art grounded in the Bauhaus and abstraction, its perceptive and sensuous qualities, once reckoned with by so many botanists working across disparate settings, beautifully described by Josef Albers in his 1963 Interaction of Color. [19] What we’re left with, beyond near-identical paint samples issued seasonally by competing corporations under evermore evocative names, is the Pantone colour system, founded in 1962 and now most immediately identifiable by its oddly off-kilter “colour of the year” announcement, translating the social value of colour and its nomenclature into a new era. [20] Pantone’s 2019’s colour, chosen because of its foreboding of our changing climate, is No. 16-1546, “Living Coral.”
Digitized herbarium sheets include small colour charts alongside rulers for scale, but one can hardly imagine botanists relying on them for any serious comparison or identification. They’re digital tools rather than material devices, designed to train an algorithm rather than the eye or hand and a far cry from ephemeral examples of earlier centuries. Most desiccated plants and faded drawings preserved in these storehouses of nature, after all, fall somewhere between brown and dull green, belying the bright and vulgar, if variable, hues of their living subjects.
Today’s naturalists have largely returned to the colour charts of the eighteenth century, working with massive printed Munsell charts in the field, matching their specimens to corresponding numbers, using the results to classify species while tracking changes over time that are usually linked to climate change–related evolution. The colours within these charts, though, have largely remained unchanged. Werner’s No. 3, “Purplish White,” once applied to geraniums and the “junction of the neck and back of the kittiwake gull” has become something akin to Pantone’s 1C, “Cool Grey” or Munsell’s N9. Their new nomenclature, matched to the same botanical specimens, prescribes new social value to these colours, carefully and imperceptibly obscuring the racial, gendered, and economic colonial histories written into their very existence.
NOTES
1/ George Ure Skinner to William Jackson Hooker, October 26, 1840 [Guatemala]. Royal Botanic Gardens, Kew, Library & Archives. Directors’ Correspondence vol. 68, f. 134b.
2/ Richard Waller, “A Catalogue of Simple and Mixt Colours, with a Specimen of Each Colour Prefix to its Proper Name,” Philosophical Transactions of the Royal Society of London 16 (1686–87): 24–28.
3/ Ibid., 28. Waller was referring to Hendrik van Reede tot Drakenstein’s Hortus Indicus Malabaricus, published over twelve Latin volumes from 1678–1793.
4/ H. Walter Lack and Victoria Ibáñez, “Recording Colour in Late Eighteenth-Century Botanical Drawings: Sydney Parkinson, Ferdinand Bauer and Thaddäus Haenke,” Curtis’s Botanical Magazine (1997): 87–100.
5/ Abraham Gottlob and Patrick Syme, Werner’s Nomenclature of Colours, Adapted to Zoology, Botany, Chemistry, Mineralogy, Anatomy, and the Arts (Edinburgh: William Blackwood & T. Cadell, 1821 [1st ed. 1814]). For the interactive site created by designed Nicholas Rougeux (C82), see www.c82.net/werner/.
6/ For the original Prussian (German) mineralogic edition, see Abraham Gottlob Werner, Von den Äusserlichen Kennzeichen der Fossilien [On the External Characteristics of Fossils] (Leipzig, 1774).
7/ James Sowerby, A New Elucidation of Colours, Original, Prismatic, and Material (London: Richard Taylor & CO., 1809), 5. See also Theresa Kelley, “Archival Objects and Material Color,” Studies in Romanticism 57 (2018): 143–68.
8/ For an extended discussion of greens and other colours liable to quick fading or bleaching, see George Field, Chromatics; or, a Treatise on Colours and Pigments, and of their Powers in Painting, &c. (London: Charles Tilt, 1835), 128.
9/ Mary Gartside, An Essay on a New Theory of Colours, and on Composition in General; Illustrated by Coloured Blots Shewing the Application of the Theory to Composition of Flowers, Landscapes, Figures, &c. (London, 1808), iii.
10/ Ibid., 6; 15.
11/ Thomas Young, “Bakerian Lecture: On the Theory of Light and Colours,” Philosophical Transactions of the Royal Society of London 92 (1802): 12–48. Young’s theory of trichromatic colour vision was later developed by Hermann von Helmholtz.
12/ James Sowerby, A New Elucidation of Colours, Original, Prismatic, and Material (London: Richard Taylor & Co., 1809), 27–28.
13/ James Sowerby, A New Elucidation of Colours (1809), 5.
14/ George Field, Chromatography, Or, A Treatise on Colours and Pigments, and of Their Powers in Painting, &c. (London: C. Tilt, 1835).
15/ John Lindley, Ladies Botany (London: James Ridgway & Sons, 1834). For a broader discussion of skin colour and art, see Angela Rosenthal, “Visceral Culture: Blushing and the Legibility of Whiteness in Eighteenth-Century British Portraiture,” Art History 27, no.4 (2004): 563–92.
16/ Marianna Torgovnick, Gone Primitive: Savage Intellects, Modern Lives (Chicago: University of Chicago Press, 1991).
17/ See, for instance, Jane Loudon, Gardening for Ladies, 2nd ed. (New York: John Wiley, 1851) and John Claudius Loudon, A Short Treatise on Several Improvements Recently Made in Hot-Houses (Edinburgh, 1805).
18/ For more on constructions of race and sex in the eighteenth and early nineteenth centuries, see Suman Seth, Difference and Disease: Medicine, Race, and Locality in the Eighteenth-Century British Empire (Cambridge: Cambridge University Press, 2018) and Surekha Davies, Renaissance Ethnography and the Invention of the Human: New Worlds, Maps and Monsters (Cambridge: Cambridge University Press, 2016).
19/ Josef Albers, Interaction of Color (New Haven: Yale University Press, 1975). See also Philip Ball, Bright Earth: Art and the Invention of Color (Chicago: University of Chicago Press, 2001).
20/ For an excellent piece on our current affective relationship with paint colour, see Daniel Harris, “Paint and Paint Names,” Cabinet Magazine 7 (Summer 2002).
Bio:
Elaine Ayers is a Professor in the Program in Museum Studies at New York University. She holds a PhD in the History of Science from Princeton University and has written about the intersections of art, science, and flora for publications including Cabinet Magazine, Hyperallergic, and The Public Domain Review.
