Blue moved from one of the rarest and most expensive colours in art history — natural ultramarine was at times valued above gold — to one of the most common and affordable colours after 18th- and 19th-century synthetic breakthroughs.
No single HEX value defines this entire colour family — see individual colour profiles below for specific shades.
Natural ultramarine, ground from the semi-precious stone lapis lazuli, was for centuries one of the most expensive pigments available, often reserved in Renaissance painting for the most important subjects.
medieval to Renaissance Europe
Prussian blue, first produced in Berlin around 1706, is widely credited as the first modern synthetic pigment, making a strong, stable blue significantly more affordable.
early 18th century
Indigo dye, produced from plants across Asia, Africa and later the Americas, was a major historical trade commodity for textile dyeing long before synthetic indigo production began in the late 19th century.
antiquity to 19th century
Blue is one of the most consistently favoured colours in modern surveys across many Western countries, and is heavily used in corporate and technology branding, often associated with trust and stability.
General
Good blue minerals are scarce. The best, lapis lazuli, came to Europe from the remote mines of Badakhshan in north-eastern Afghanistan, and yielded the most expensive blue a painter could use. What changed blue's standing was manufacture. Smalt, a ground cobalt glass, appears in European paintings from the 15th century. Prussian blue was discovered in Berlin around 1704. Then, within twenty-five years at the start of the 19th century, came cobalt blue, cerulean blue and an artificial form of ultramarine. Each was cheaper or more dependable than what it replaced, and the artificial ultramarine was used extensively by the Impressionists and the painters who followed them. 1, 2, 3, 4, 5
| Name | Kind | Period | What is known | Sources |
|---|---|---|---|---|
| Natural ultramarine | Pigment | medieval to early modern Europe | Extracted from lapis lazuli. It is the brilliant blue of the Virgin's robe in Sassoferrato's The Virgin in Prayer, in the National Gallery. | 2 |
| Azurite | Pigment | antiquity to about the early 18th century | The everyday mineral blue. It is present alongside ultramarine and indigo in the Wilton Diptych. | 6, 7 |
| Smalt | Pigment | 15th to about the 19th century | Finely ground glass coloured with cobalt. It can lose its colour in old paint as potassium leaches from the glass. | 3, 8 |
| Prussian blue | Pigment | from about 1704 | An iron-based synthetic. Stable alone, but liable to fade where mixed with a great deal of white, as in some 18th-century skies. | 4, 9 |
| Cobalt blue and cerulean blue | Pigment | from 1803–05 | Two cobalt-based blues first made within two years of each other; cerulean was used mainly for skies. | 10, 11 |
| Artificial ultramarine | Pigment | from 1828 | After 1828 it rapidly took the place of the natural pigment. Van Gogh's deep blue sky in The Starry Night is predominantly this. | 5 |
| When | Where | What happened | Sources |
|---|---|---|---|
| 1550s to 1620s | England | 'Indigo' enters English, first as indico for the blue powder obtained from plants and then, by the 1620s, as the name of its colour; the word goes back to a Greek term meaning the Indian substance. | 12 |
| About 1704 | Berlin | Prussian blue was discovered, giving painters a strong manufactured blue that did not have to be mined. | 4 |
| 1805 | — | Cerulean blue was first synthesised, a light and very stable blue. | 11 |
| 1880–86 | — | Renoir's The Umbrellas records the changeover within one canvas: the clothes of the mother and daughters on the right are in cobalt blue, the grey-blue dress of the woman on the left in artificial ultramarine. | 5 |
| 2017 | United States | YInMn blue, discovered eight years earlier, was cleared by the environmental regulator for use in industrial coatings and plastics. Its manganese ions absorb red and green light and reflect only blue. | 13 |
Claim: Ultramarine was reserved for the robe of the Virgin Mary.
Evidence: Too narrow. It was certainly used that way, and the National Gallery points to a 17th-century example. But in the Wilton Diptych, painted for an English king, ultramarine also forms the pattern on the robe of Saint Edmund, a royal saint. The pigment marked importance and expense; the Virgin's mantle was its most frequent use, not its only one. 2, 7