A Brief History of Colour

My life and fortunes are a monstrosity,
Partly because of Hera, partly because of my beauty.
If only I could shed my beauty and assume an uglier aspect The way you would wipe colour off a statue.

In this passage from Euripedes, Helen of Troy remorsefully questions the essence of beauty. She compares the act of removing paint from a statue’s surface to disfiguring a goddess.

Euripides’ exclamation in Hypsipyle likewise encourages us to visualise the ancient Greek world splashed in vivid, extraordinary hues:

But look! Take the trouble to cast your gaze upward, and marvel at the painted sculptures in the gable!

Colour was inextricably linked with beauty in the ancient world, and many ancient statues were actually painted in bold and daring fashions – far from the plain and polished lily-white marble statuary we see adorning temples and streetscapes today.

How did these ancient civilisations come to create and apply these bold colours, long before the invention of modern paints? Join us as we dive into some of the theory of paint, and what ingredients were used to create paints in history.

Pigments, paints and dyes – oh my! What are the exact differences between these terms?

It might seem elementary to define paint, but our other definitions will build from here. Simply, paint is the term for a mixture of two things: a colourant and a medium. Colourants, such as dyes and pigments, can be unwieldy on their own. The practice of mixing these into a medium – such as water, oil, egg or more recently acrylic – emerged out of the need to make the colour easier to apply, spread and control. Medium is sometimes also referred to as vehicle or carrier.

As mentioned above, pigments and dyes are both colourants that provide the colour to a paint when combined with a medium. But, pigments and dyes act differently and are suited to different uses. This is due to how they act on a particle level.

Firstly, pigments are a suspension and dyes are a solution. What does this mean?
Arts and crafts site The Blue Bottle Tree offers this anecdote to explain:

When you scoop a cup full of muddy water from a puddle, the water is brown. There are silt and dirt and mud particles suspended in the water. Given enough time, without being disturbed, the particles will settle out of the water and collect on the bottom of the cup. … Chemically, this is called a suspension.

If you mix a spoonful of sugar into a cup of water, the sugar will completely dissolve into the water. If you let the cup of sugar-water sit, capped to avoid evaporation, on the shelf for a long time you will never get a layer of sugar particles settling on the bottom of the container. Chemically, this is called a solution.

So: pigments are finely ground particles of colour that are completely or nearly insoluble. When mixed into a medium, they are suspended – just like the muddy puddle. (And in fact, some of the earliest pigments were coloured earth, like mud and clay – more on this soon.)

Meanwhile, dyes are soluble chemicals that dissolve into a medium. Early dyes were made from natural chemicals extracted from plant matter, and later, synthetic dyes were invented. Many Greek families will be familiar with a fun example of natural dye – using onion skins to dye eggs for Orthodox Easter!

Another noteworthy difference is that pigments are most often inorganic compounds – a chemical compound that lacks carbon–hydrogen bonds – while dyes are most often organic compounds – which do contain carbon–hydrogen or carbon–carbon bonds.

Like paint, ink is a term for a mixture of colourant and medium, though inks can be a more complex solution with additives like solvents, resins, surfactants and more. These serve to affect the flow of the ink, which is often used for writing, drawing and printing – applications that require a smooth flow of colour for fine detail control. Inks throughout history have used both pigments or dyes as their colourants. Art inks, like Indian ink are often pigment based, while others like permanent markers or stamp pads are typically dye based.

Should you use a paint, or an ink? Should it be pigment or dye based? What medium should it be mixed with? These decisions will be influenced by factors such as what you are creating, the surface you are colouring onto, how lightfast or well-preserved the finished work needs to be. These considerations mattered in history as much as they do today, and in addition to considering the accessibility of certain colours, influenced the development of colourants and paints across history.

These are some of the most common mediums used to mix colourants into paint – though certainly not all of them!

Water has been used as a medium since the earliest known paintings. In very early paintings which used coloured earth as their pigment, water naturally moistens the earth to make it more malleable, and could be used to thin the earth even further.

Tempera is related to water as a medium, as it is an umbrella term for a range of water-based binders, mixed with colourants to ‘temper’ them. These binders have historically included gum arabic, animal glue, casein or even egg white. (Egg tempera, paint made from egg whites, was popular in ancient Greece!)

In the 15th Century, oil found popularity as a medium. This is often attributed to the Flemish painter Jan van Eyck, though it is believed that oil paints were in use for some time before he brought them to the fore. They are most commonly made with linseed oil, but poppy, sunflower, safflower and walnut have also been used.

This is likely the medium you are most familiar with, but it’s at the bottom of this list as it is the most contemporary – acrylic medium was only invented in the 1930s! The acrylic is water soluble, but once the paint dries (i.e. all of the water evaporates from it) it becomes water fast, which is just one of the reasons it was widely popular by the 1960s.

These are the stories behind some of the pigments and dyes used in history.

Ochres were some of the very first pigments used by humankind. These colours, along with bone white and bone black have produced lively depictions of animals, humans and spirits which adorn rock faces and cave walls the world over. They were especially prized in pre-colonial Australia where coloured earth was known to be traded between language groups.

As time passed the processes of pigment making were refined. Fire was employed to turn natural ochres a richer colour, from yellow to orange, red and brown. These colours are referred to as ‘burnt’ – like burnt sienna.

For thousands of years, humans made the treacherous journey across the mountainous province of Badakhshan, Afghanistan, seeking the precious gem lapis lazuli. This blue stone was rare, and expensive and laborious to refine, so the paint made from it was reserved for special decorations or important figures in an artwork, like the Virgin Mary. Modern systems have made lapis more accessible today, where it is still in use by some artists.

By the time of the pharaohs, around 5000 years ago, the science of colour had progressed to the point that the first ‘synthetic’ colours were being developed. Egyptian Blue, inspired by the extremely rare, naturally occurring minerals like lapis lazuli and azurite, was made by heating lime, silica, natron and copper. Initially this produced a glaze known as faience but even further experimentation proved that maintaining the temperature of a kiln at near 830°C produced a potent, opaque blue that could be applied as a paint.

Egyptian Blue spread from Mesopotamia to Greece, to Rome and from there to the very ends of the Roman Empire. The walls of Knossos were enlivened with Egyptian Blue, as were those of Pompeii and Assurnasirpal II’s palace in Assyria amongst many others.

Cinnabar, Vermilion & Red Cadmium

Cinnabar is a mercury sulfide mineral that was used from antiquity, through to the present, although only scarcely due to its toxicity. From the 8th Century, vermilion, an artificial dupe of cinnabar was popularised as it was more accessible than its dangerous counterpart. Vermilion was the principle red used in painting until the manufacture of its synthetic equivalent, cadmium red, which was created in 1919 by heating cadmium yellow combined with selenium.

Thousands of years ago, Mesoamericans found that when they squeezed an insect found on a prickly pear cactus plant, their fingers and fabrics were stained blood-red. Found in Mexico, Central America and South America, the females of the species coccus cacti feed on the red berries of the cactus and produce an intense red chemical.

Cochineal became a highly prized dye, after Europeans reached Mexico and found that the Indigenous peoples’ red fabrics were far more vibrant than anything they had seen. The laborious process of harvesting the insects made this a very expensive product. Once collected from the cacti, the insects are delicately rolled to kill them without damaging the chemical, and are left to dry. To produce a single pound of cochineal pigment, requires 70,000 insects!

The use of cochineal by artists rapidly decreased following the mass production of artificial red pigments such as alizarins in the nineteenth century.

Also known as Phoenician Red, Tyrian Purple is a colour created by ‘milking’ mollusks that were found on the Mediterranean and Atlantic coasts. When broken and squeezed by hand, they secrete a white fluid in which cloths would be dipped. Exposed to strong sunlight, the secretion would chemically develop into a purplish red or crimson, depending on the species of mollusk and the exact extraction process used.

This painstakingly manual process and the number of mollusks required made this one of the most costly colouring methods, and is how purple came to be associated with power and royalty. Tyrian Purple was the colour in the togas of Roman emperors, giving rise to the expression ‘born to be purple.’ It was also used in the preparation of purple ink and dyed parchments upon which the codices of Byzantium were written.