Nature’s own shades of colour

Natural colour shades from fruit and vegetable dyes. Photograph by Heather Schrock

Like most gardeners, during the summer I often (or I should really say ALWAYS!) buy new plants – especially after this year’s period of garden centre closures in the spring. One purchase this summer was a pretty pink Black-Eyed Susan, Thunbergia ‘Pink Sensation’. As it wasn’t in flower, the only guide I had as to the eventual colour of the flowers was the photograph on the label. This happens all the time of course, and I didn’t think much about the actual shade of pink of the flowers to come. But an article in The Gardeners’ Chronicle of 3rd May, 1913 (which I came across while researching something else entirely) made me stop and think about the different shades of colour in our gardens, and how they’re described in the horticultural world.

Thunbergia ‘Pink Sensation’

The article in The Gardeners’ Chronicle was reporting on an RHS Award of Merit given to a small, pretty alpine covered with bright pinkish flowers, Aethionema armenum, shown by Miss Ellen Willmott of Warley Place fame. What caught my attention however, was the additional description of the colour of the flowers as “very pale violet-rose, 154 of the Repertoire de Couleurs”. Intrigued by this, I discovered on the web that the Repertoire was a French colour chart published at the beginning of the 20th century – a forerunner of today’s RHS Colour Chart used worldwide for recording plant colours (more on which later).

Aethionema armenum ‘Warley Rose’

Plate 154 – Rose violace

(rose-violet) from the

Repertoire de Couleurs by Oberthur & Dauthenay, 1905

I hadn’t really considered that, in the past, shades of different colours had had to be standardised, and ‘named’, just like the plants themselves. The simplest definition of colour that I found seems to be that “it’s a property of light as seen by people” (see simple.wikipedia.org) but, as we know, people often perceive colours slightly differently. For example, scientific experiments show that there are definite differences between the sexes in how they see shades of colour. (There’s a lot of information on this aspect of colour perception on the internet if you wish to know more.)

The Repertoire was not, however, the first attempt to standardise the description of different shades of colour. The Greek philosopher Aristotle is credited with developing the first known theory of colour. He believed colours were sent by God, and these beliefs were widely held for over 2,000 years until Sir Isaac Newton’s experiments with light in the mid-1600s. Newton discovered, as I recall being taught at school, that a beam of light could be split into a spectrum of different colours by passing it through a prism. And it was Newton who later produced the first rudimentary type of colour wheel.

Unfortunately, Newton trusted maths rather than the eye, and many remained unconvinced by his colour wheel. Over the next 150 years many works on colour followed, until the late 18th century when German mineralogist, Abraham Gottlob Werner, devised a standardised scheme for classifying colours.

However, it was the German thinker, Goethe’s, theories on colour, published in 1810, that concentrated more on how we actually see colour. And this really changed how colour was perceived in a more scientific way.

Goethe's symmetric colour wheel, with associated symbolic qualities, 1809

But it was a Scot, Patrick Syme, who published one of the best guides for colour classification of the time when, in 1814, he adapted and revised Werner’s ideas publishing them under the title Werner’s Nomenclature of Colours with additions by Patrick Syme (Flower-Painter, Edinburgh). Charles Darwin is known to have taken a copy of Syme's book with him on his five-year voyage on The HMS Beagle, relying upon it to aid in his descriptions of the many species he collected.

In the book, Syme summarised the problem of the lack of standardisation in colours at the time:

“A nomenclature of colours, with proper coloured examples of the different tints… has been long wanted in arts and sciences. It is singular, that a thing so obviously useful… should have been so long overlooked.

To remove the present confusion in the names of colours and establish a standard that may be useful in general science, particularly those branches, viz. Zoology, Botany, Mineralogy, Chemistry…is the object of the present attempt.”

One of Syme's greatest enhancements to Werner’s original guide was to include painted swatches for each colour, based on Werner’s precise descriptions, with examples of where to find the colours in the natural world. The hundreds of colour samples published allowed artists, scientists, and naturalists to standardise the vast array of different shades of colour found in nature, as well as describing where each specific shade could be found on an animal, plant or mineral - as can be seen in the extract from the palette of 'Greens' below. For example, Verdigris Green is the given colour for the "tail of small Long-tailed Green Parrot"! Additionally, the book's poetic colour names - such as Arterial Blood Red and Broccoli Brown, added a more vivid vocabulary for writers and researchers than previously available.

Examples of colour palettes from Werner’s Nomenclature of Colours

A few years later, another artist, William Burchell, tried his hand at colour charts, producing several between 1825 and 1830 to help in his identification when plant collecting in Brazil. The chart shown below has 60 colours ranging from ‘White’ to ‘Indian Ink’, and Burchell used it (and similar charts) extensively when cataloguing his approximately 52,000 Brazilian specimens. These catalogues are still regarded by naturalists as important records of Brazilian botany, and are held at Royal Botanic Gardens, Kew.

Detail from a colour sample sheet painted by William Burchell. Image from RBG Kew's 2019 exhibition, Nature's True Colours

Fungi were not to be left out, getting their own colour-naming system when Pier Andrea Saccardo, an Italian botanist and mycologist, published his Chromotaxia Scale in 1891. Unfortunately, as the printing processes of the time often created differences in different print runs, causing confusion over the original colours, it was not hugely successful.

Chromotaxia Scale by Pier Andrea Saccardo, 1891

The next major colour classification work was the previously mentioned Repertoire, published in 1905 by Rene Oberthur and Henri Dauthenay – its full title translating as ‘Colour directory to help determine colours of flowers, foliage and fruits’.

And so to the RHS Colour Chart: first published in 1938 in order, according to the scientific journal, Nature, to “meet a pressing need” to update previous standard works on colours which were either out of print or too expensive to have a wide application (Nature, 138, 1936). This first chart consisted of just 100 loose plates of printed colour samples. The RHS chart is now updated every few years and the latest, the sixth, was published in 2015. The RHS describes its chart as “the standard reference used by horticulturists worldwide for recording plant colours. Resembling a paint chart, it has 920 colours which can be matched precisely to flowers, fruits and other plants in order to record and communicate colours accurately across the world. Each colour has a unique number and letter code as well as a name”. The chart is also used in industries such as food, cosmetics, pharmaceuticals and fashion.

I’m not about to splash out £199 on an RHS Colour Chart and check all the shades of colours in my garden, but I did check my new Thunbergia against the Repertoire and, somewhat to my surprise, the nearest match was ‘pale violet-rose, 154’.

RHS Colour Charts

And talking of paint charts it’s interesting that, in the last few years, both paint manufacturers and design companies have caught on to society’s greater interest in nature - the state of our planet, habitats and biodiversity, and often equate their paint colours with the shades and hues of colour in nature in the names of their colours and their advertising. Below is one example - an advertisement for paint colours in Better Homes magazine.

Advertisement in Better Homes for paint colours

While, on the web, I found one design company, Design Seeds, who produce inspiring colour schemes for their clients using nature's colours, as can be seen below.

Getting slightly off the subject of natural colours, you've probably heard of Pantone colours, often in relation to 'Pantone Color of the Year', which is eagerly awaited by the design and fashion world in particular. The US Pantone Color Institute is the leading global colour-matching system, and are experts in how colour effects design and consumerism. They have a palette of over 1,000 colours, slightly more than the RHS's 920 colour shades.

I've often seen Pantone Color of the Year mentioned in fashion and design magazines, whose editors inform us what colour we'll all be wearing or what colour sofa we'll be buying in the coming season. However, I was somewhat surprised to learn that their Color of the Year is decided upon a year before at a 2-day meeting of representatives from various countries' colour standard groups - the meeting always held in a European capital. The results, published in Pantone View, are snapped up by the awaiting fashion designers, florists, and many other consumer-oriented companies, to assist with their use of colour for their future designs and products. The chart below shows all the Pantone Colors of the Year from 2000 through to 2020 - with 2016 unusually having two!

'll finish my brief romp through the story of how nature's shades of colours were named, by mentioning two particular books on how to use colour in the garden (although there are, of course, many articles and books available on this subject). Perhaps the most famous recent promoter of being bold with colour was Christopher Lloyd of Great Dixter fame with his book Colour for Adventurous Gardeners (2001) – its first chapter entitled, ‘Colour. Go for it!’. Fortunately, his ideas on colour are still exercised at Great Dixter today, as can be seen in the photograph of their spring display of pots in 2018.

Great Dixter in Spring Time. Image greatdixter.co.uk

More recently, Gardeners’ World presenter Nick Bailey’s book, 365 Days of Colour in your Garden (2015) covers the “infinite variability of plant colour in gardens” with chapters on ‘The Art and Science of Plant Colour’, and ‘The Colour Wheel for the Gardener'. As he writes, “colour is such a joy to experiment with… the possibilities are endless”.

After all, you have 920 shades to play with!