In this series, we explore the stories behind certain pigments - natural and synthetic - and how these hues, and artists’ understanding of color in general has impacted the development of art.

Most people probably have hazy memories from school about rays of light travelling in waves. They might also recall that Isaac Newton once passed one of these rays through a prism, leading to a major discovery. It turned out that light wasn’t ‘white’ - or rather, it wasn’t simply white. It actually contained within it all the colors of the rainbow.

However, before we get to that, it’s important to remember that we tend to use the word color in two different ways. We might be referring to the visual sensation in the brain caused by light being made up of differing wavelengths. Or we might just be talking about pigments - the powdery substances that are mixed with a liquid (known as a ‘vehicle’) to make paint.

Pigments

The earliest pigments used by humans were essentially just different types of mud. Despite these humble origins, pigments have played a profound role in shaping human culture, from its earliest beginnings in pre-history all the way into modern times. From Africa to Australia, what all ancient cave art had in common was not just the imagery (mostly animals), but the colors. Yellow and red ochres were used everywhere by early humans, made from iron oxide dug out of the earth, ground into a fine powder and then mixed with either blood or animal fat.

The first pigments came from minerals and clays, but with the rise of civilisations during the Bronze Age, humans started to make synthetic pigments. For instance, the Egyptians made blue and green out of copper, whilst white was made from lead. Over time, further colors were added, such as vermillion from cinnabar and Indian yellow from the urine of cows.

Nonetheless, until the 19th century, there was still only a relatively small number of colors available for the artist’s palette. This is where science and technology stepped in. The discovery of new metals such as chromium during the Industrial Revolution meant that by the end of the 18th century, more colors had become available. By the mid-19th century, this trickle had turned into a torrent, as all manner of novel pigments were being manufactured in high volume. French ultramarine replaced the eye-wateringly expensive lapis lazuli, whilst cadmium reds, yellows and oranges were indicative of a new generation of pigments that were stable, brilliant and cheap. By opening up new artistic possibilities, these innovations in color made Impressionism itself possible. At the same time, the invention of airtight metal tubes for storage made painting outdoors (‘en plein air’) practical for the first time.

In the Eye of the Beholder: Realism vs Symbolism

There has always been a tension at the heart of how color is used in art. It has often been a vehicle for emotional and symbolic expression, but also a tool for accurately representing the world around us. For instance, artists over the centuries have figured out clever ways of using color to trick the eye into believing that a flat two-dimensional canvas actually has depth. Mimicking aerial perspective, distant objects are painted bluer and greyer so as to appear to recede in space. Conversely, by making objects warmer in the foreground of a picture, they seem to advance.

However, color has also been used as a symbol. In the earliest cultures, red was often seen as the color of life, yellow the symbol of fire. The Ancient Egyptians would allocate particular colors to their gods to symbolize their religious functions. In the twentieth century, abstract artists such as Kandinsky continued this tradition of using color to convey an idea, rather than as a way of representing outward appearances. In Kandinsky’s case, he wanted to reveal the innermost feelings of the artist. Colors were carefully chosen for their emotional effect on the viewer.

This more subjective relationship with color was itself a reaction to the ‘objective’ naturalism of Impressionism a generation earlier, which had sought to paint honestly what the eye sees. It wasn’t simply the invention of new pigments that had inspired artists such as Monet to capture the fleeting effects of light. The Impressionists were also reflecting groundbreaking scientific advances in the understanding of color.

Color theory

For most of human history, there was no scientific theory of color. Artists generally used a mixture of experience, tradition and instinct to guide their color choices. Newton’s discovery that light travels in different wavelengths led to the realization that ‘white’ light is actually composed of the seven colors of the visible spectrum. Violet, indigo, blue, green, yellow, orange and red. We ‘see’ a color thanks to our brain interpreting these varying wavelengths as different colors. The pigments used by an artist appear to be a particular color only because they absorb certain wavelengths and reflect others. The color of paint is therefore nothing more than this reflected light returning to our eye.

The 19th century witnessed a revolution in the theoretical understanding of color. At the forefront of this change was the French chemist Eugéne Chevreul and his ‘Chromatic Circle’. The ‘primary’ colors of red, yellow and blue are known as such because they cannot be mixed from any other color. By mixing these primaries together, the ‘secondary’ colors of orange, green and violet can be made. Chevreul realized that by placing certain colors next to others, they would appear brighter thanks to the resulting visual ‘vibration’. Famously, the Impressionists took advantage of this latest discovery. Rather than mixing a color together on their palette, they placed two complementary colors side by side on the canvas in order to intensify the effect - blue next to orange, red next to green, yellow next to violet.

The Future

Color still plays an essential role for the artist of today. Technological change and advances in digital imagery continue to open up new vistas. Even new discoveries in pigments play their part. In 2016, the contemporary artist Anish Kapoor controversially bought the exclusive rights to use Vantablack, the ‘blackest’ black ever made, thanks to its ability to absorb 99.965% of visible light.

Color still has the power to move us, as well as the ability to describe the world around us. Arguably, we’re just continuing the tradition that our ancestors began in those dimly lit caves thousands of years ago. Although, thankfully, we now have a much bigger palette.