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Yves Klein, “IKB 191”, 1962. Image via Wikimedia Commons.
The word “blue” comes from the French word bleu, which refers to one of the primary colours that are vivid to the human eye. However, for many ancient civilisations, blue was often indistinguishable from green or black. In Homer’s epics such as the Iliad or the Odyssey, there is no specific term for blue. Instead, Homer described the sea as “wine-dark” rather than blue. This fact itself indicates that the perception of colour, as we understand it today, was quite different from that of ancient times. In fact, in many languages, there is no clear distinction between “blue” and “green” as separate colours, and the colour blue was one of the last hues to gain recognition in many cultures’ lexicon.
Blue has been valued above all other colours in art for centuries, from its rarity in nature and the effort required to produce it. Across cultures, blue pigments were used for three special purposes such as symbolising the celestial colours of the sky and heaven , conveying prestige, status and wealth or for garments worn by Devine – sacred figures or high-ranking clergy.
In ancient Egypt, for instance, gods like Kneph, the Creator, were depicted in blue robes to signify their celestial origins, while Isis was called the “Lady of Turquoise,” and Osiris was associated with turquoise and lapis lazuli. In Norse mythology, Odin, the wise All-Father, is frequently described wearing blue robes, underscoring his connection to wisdom and the divine. Similarly, in Assyrian mythology, the god Sin was said to have a blue beard, highlighting his otherworldly nature. For the Greeks, Homer described Pallas Athena, the Goddess of Wisdom, as the “blue-eyed maid,” a symbol of insight and intellect. Even among the ancient Celtic Druids, blue was the colour of the bards’ robes, linking the colour to knowledge, tradition, and spiritual authority. In Hinduism, blue is associated with deities like Krishna and Vishnu.
From a chromatic perspective, blue pigments are classified into two categories based on their undertones: cool blues, which lean toward violet, and warm blues, which incline toward green.
Egyptian Blue
Egyptian blue, invented around 4,500 years ago, holds the distinction of being the first synthetic pigment and a testament to ancient technological innovation.
Created through a sophisticated process, it involved heating a mixture of lime, quartz sand, alkali, and copper-bearing materials (such as malachite) to approximately 830°C in kin for several hours, resulting in a glassy compound that was ground into a fine powder. This copper-based pigment when exposed to ultraviolet light emits infrared light, adding a mystical quality to the artefacts it adorns. It is highly stable and retains its vibrant colour over millennia. Used extensively in murals, temples, sculptures, ceramics and sarcophagi, Egyptian blue was rediscovered during excavations of Pompeii in the XVI and XVII centuries. However, its chemical composition was not understood or replicated until the 1880s.
Production was so successful that it spread in ancient Rome and Greece. However, by the 5th century, it was replaced by naturally occurring mineral pigments like ultramarine and azurite. These pigments, prized for their vibrant hues and increased availability, dominated the art world for centuries.
The rich blue colour was associated with the sky, water, and the divine.
Azurite
Azurite pigment played a crucial role in art history due to its relative accessibility to Ultramarine or Egyptian blue. It is a natural copper-based mineral, that often occurs alongside the green mineral malachite. Artists extracted the pigment by crushing, washing, and grinding the mineral into a fine powder. It was valued for its chemical stability and vivid colour, and particularly for rendering skies, fabrics and religious iconography.
It was widely used in Europe for manuscripts, panel paintings and murals during the Middle Ages and Renaissance. In China known as qing dai (青黛) it was used in traditional paintings and ceramics. While in Japan prominently used in Nihonga (Japanese-style paintings).
Natural Ultramarine (Lapis lazuli)
Lapis lazuli and the pigment directed from it – ultramarine, have been recorded in history as some the most admired and precious materials in art and culture for millennia. The vivid hue, rarity and symbolic significance of the deep blue of lapis lazuli have been appearing in Byzantine manuscripts and mosaics, Afghan and Persian art used in murals paintings and miniatures, and Indian and Chinese artists used lapis in illuminated manuscripts, paintings and ceramics.
Lapis lazuli is primarily sourced from the the Sar-e-Sang mines in modern-day Afghanistan, which have been active for over 6,000 years. Smaller deposits exist in Iran and other regions. The term “ultramarine” originates from the Italian oltramarino (meaning “beyond the sea”), alluding to its importation into Europe from the East.
Extracting ultramarine from lapis lazuli was labour-intensive and yielded minimal pigment. The process, developed by Arabic alchemists in the IX century, involved grinding into a fine powder, and meticulously removing impurities like calcite and iron pyrite. The powdered stone was kneaded with waxes, resins, and oils, and then immersed in a weak lye solution to dissolve and separate the blue particles. Even tiny amounts of impurities could dull the vibrancy of the final ultramarine.
By the Renaissance, the ultramarine was more expensive than gold and considered a luxury reserved for subjects embodying spiritual beauty and perfection. It is luminous and rich blue hue was ideal to represent adorned skies, halos, and garments in religious paintings, and depictions of Mary.
Till today Ultramarine remains an enduring symbol of luxury, spiritual transcendence and craftsmanship.
Prussian Blue and Aizuri-e
Prussian blue marks a transformative moment in the history of pigments, opening door to the era of modern synthetic colours. It was discovered accidentally in 1704 by chemist Johann Jacob Diesbach. He attempted to create a red pigment using iron sulfate and potash contaminated with animal blood, which instead yielded a vivid and stable blue.
Initially used as a fabric dye, Prussian blue formula spread quickly across Europe due to its affordability and versatility. It became a staple for artists like Watteau, Canaletto, and Gainsborough. The ability to mix with other pigments as its strong tinting power it gave artists new possibilities for creating shadows, says, and atmospheric effects/
Prussian blue was introduced to Japan in the late XVIII century through trade with China and the Dutch East India Company and quickly gained huge popularity among Japanese woodblock printing.
With the Prussian blue technical sophistication, Katsushika Hokusai and Utagawa Hiroshige elevated ukiyo-e to a new height. Hokusai used Prussian blue to create the iconic series Thirty-Six Views of Mount Fuji (c. 1830–1832), including the famous The Great Wave off Kanagawa. The deep blues of the ocean waves and sky in these works are due to the vibrancy of Prussian blue.
The pigment’s stability enabled the development of innovative techniques like bokashi, which gradates colours to create depth and evoke infinity.
Phthalocyanine Blue
Phthalocyanine blue (PB15) is a modern synthetic pigment discovered in 1907 and commercialized in the late 1920s. Renowned for its intense, vibrant hue, and exceptional durability, it surpassed earlier pigments in versatility and affordability.
Phthalo blue is a bright, intense blue with high chroma and clarity, highly resistant to fading and chemical exposure. Its versatility allowed for use in diverse mediums such as oil, acrylic, watercolour paints.
Phthalo blue features prominently in modern art, especially in the works of American abstract painter Sam Francis, who extensively in his works uses Phthalo to evoke depth and energy.
Today, it remains one of the most widely produced and used pigments in the world. Finally quest for the “perfect blue” reached its culmination continuing the lineage of historical pigments like Egyptian blue, ultramarine, and Prussian blue.
Yves Klein
A young French artist Yves Klein patented his own version of ultramarine in 1960 under the name International Klein Blue (IKB). IKB became a hallmark of Klein’s art, featuring prominently in his monochrome paintings, sculptures, and performance art.
This rich history of blue pigments illustrates their profound impact on art and culture, symbolizing beauty, divinity, innovation and the infinite across millennia, leaving an indelible mark on the human experience.
