More muted than lapis or cobalt, it was used as a body paint by early Britons (Julius Caesar saw it when the Romans invaded England), perhaps because it is a mild antiseptic. William Wallace is said to have used it, hence Mel Gibson’s half-blue face in the film Braveheart. In India at the same time, the main textile dye was indigo, which is closer to purple than the others.
The development of the silk trade route between Asia and the Mediterranean led to the flourishing of indigo. It became so valued that less than five years after painting the Mona Lisa, Leonardo was contractually required to use it in his beautiful The Virgin of the Rocks. This London version of the painting is perhaps a copy, in part by his assistants, but it demonstrates well the use of blue.
The indigo was underpainted with another blue, azurite, this time derived from a copper carbonate. You could call the painting bichrome. Two colours, blue and gold, each precious, are embedded in each other. They seem to swirl like oil on water. The painting has a religious subject, of course, but at this early stage in the story of looking, it is the reduced colour palette, the way the Madonna’s gown echoes the distant hills, that catches our attention.
A century after Leonardo, Persian blue came to dominate the intricate tile work of the great mosques in Iran. Again the subject was religious, but even more than in The Virgin of the Rocks, the blue-gold combination gestures to abstraction.
When it is mined, azurite is veined with earth colours. It is hard not to see the colour scheme of the mosque, and maybe even the Madonna, in these naturally forming blue-brown combinations. They evoke earth and sky.
And so, as the word appeared in more languages, and more sources of blue were found in nature, and as our art and buildings became more blue, so did human life. As Alexander Theroux, who writes brilliantly on colour, describes:
It is the symbol of baby boys in America, mourning in Borneo, tribulation to the American Indian, and the direction south in Tibet. Blue indicates mercy in the Kabbalah and carbon monoxide in gas canisters. Chinese emperors wore blue to worship the sky. To Egyptians it represented virtue, faith and truth. The colour was worn by slaves in Gaul . . . A blue spot painted behind the groom’s ear in Morocco thwarts the power of evil, and in East Africa blue beads represent fertility.
He is telling the anthropological story of blue and how it shifts in appearance, meaning and effect.
LOOKING AND THE COLOUR WHEEL
But how does blue relate to all the other colours in life? In the late 1700s a Frankfurt-born artist, writer, lawyer, statesman, philosopher and collector had this question in mind. He travelled to Italy to see great art, and wrote about Leonardo da Vinci. What he saw in Italy led, in 1810, to his Theory of Colours, one of the most influential publications on the subject. It was a wayward work, contradicting the science of its day by emphasising not the optics of colour, but how we look at it, how it works on our imaginations. ‘Search nothing beyond the phenomena, they themselves are the theory,’ he wrote, a manifesto of looking. His name was Johann Wolfgang von Goethe.
Goethe sensed that colours tamper with each other, and with blackness. Of our colour, blue, he wrote ‘it is darkness weakened by light’. To scientists this was nonsense, but Homer’s descriptions of the sea in The Odyssey seem born of the same thought. Goethe’s was an artist’s account of light, and it influenced painters such as J.M.W. Turner. And Goethe’s ideas can certainly help us understand why in Leonardo’s Virgin of the Rocks, the Iranian mosque and the raw azurite, the colours seem so right for each other.
Here is an image of Goethe’s from 1809:
In his Theory of Colours he explained its significance.
The chromatic circle . . . is arranged according to the natural order . . . The colours diametrically opposed to each other in this diagram are those which reciprocally evoke each other in the eye. Thus, yellow demands violet; orange [demands] blue; purple [demands] green; and vice versa.
Just as Goethe predicts, diametrically opposite our blues is the yellow-gold of Leonardo and the Iranian mosques. They reciprocally evoke and even demand each other. Though he had no scientific proof for this, Leonardo wrote that colours ‘retto contrario’ – totally opposite – each other are the most harmonious. And in 1888, in a letter to his brother, painter Vincent Van Gogh wrote of the ‘antithesis’ of colours. His most famous painting, The Starry Night, is blue and yellow-gold. Stare at blue for half a minute, then look at something white, and what do you see? Yellow. After forcing blue upon your eye and brain, it is as if they – to use Goethe’s word – demand the complementary after-image, yellow.
And Goethe helps us understand other aspects of looking at colour. Both the Leonardo paintings we have seen so far depict distance, z-ness, as blue. This moment from the 2002 Chinese film Hero does the same. Despite the cloud, the trees in the landscape on the left are somewhat green. In the distance, on the right, there is a noticeable indigo shift. The film-makers emphasise this by dressing the figure in the image in the same colour.
Goethe explains this blue shift. He did experiments to show that when light travels through the moisture and dust in the air (what he called turbid media) it becomes coloured. It had long been known that white light is split as it travels through a prism (or raindrops – hence rainbows), but in the Theory of Colours Goethe describes this refraction in a way that would have been useful to Leonardo, or Christopher Doyle, who filmed the above shot in Hero:
If . . . darkness is seen through a semi-transparent medium, which is itself illumined by a light striking on it, a blue colour appears: this becomes lighter and paler as the density of the medium is increased, but on the contrary appears darker and deeper the more transparent the medium becomes: in the least degree of dimness short of absolute transparence . . . this deep blue approaches the most beautiful violet.
And as well as complementary colours, and distance, Goethe wrote about something else that opens our eyes. He said that all hues are coloured shadows, which is implied in his comment on blue. But it is the phrase ‘coloured shadows’ which is evocative.
In the image below, a man who has long wanted to see this woman this way, finally does so. It is from Alfred Hitchcock’s film Vertigo. The man was in love with a woman who died (or seemed to), then met another woman who resembled her. He wanted to remake the second woman as the first, to pretend to himself that she had not died, or to gratify his erotic imagination. Hitchcock and his cinematographer Robert Burks film the scene as the man sees it, or rather, feels it.
Look at her shadow, which falls across the bed and onto the wall. Is it grey, like shadows are supposed to be? No, it is plum coloured, like the lampshade, both of which, on the colour wheel, are the opposite of the green of her dress. We think of a shadow as an absence of light, but not for Goethe, and not here. A shadow is not necessarily just less, a reduction: here it is a contortion. The darkness is alive. Even it has something to say.
Then follow that thought to this image: