The Colour of The Season: The Story of Klein Blue

Yves Klein was born in 1928 in Nice, in the south of France. The son of two painters, one might assume that his relationship with colour emerged directly from his immersion in art. Yet his fascination with blue came from something far more elemental: his observations of the Mediterranean sky.

On many occasions, he spent hours contemplating the infinite ultramarine dome above him. For Klein, that sky represented a spiritual experience, something he summarised in one of his most famous reflections: “Blue has no dimensions, it is beyond dimensions.”

When Klein began working in the 1950s, his interest in colour soon developed into a radical artistic project. In 1955, he presented in Paris a series of monochrome paintings in different colours, a proposal that marked a drastic reduction in the variety of pigments used in his work.

The true turning point arrived in January 1957 with an exhibition at the Galleria Apollinaire in Milan. There he presented eleven identical canvases covered in an intense ultramarine blue, installed slightly away from the wall so they appeared to float.

“Each of those blue worlds, although painted with the same blue and the same technique, revealed a completely different essence and atmosphere.” Yves Klein, The Monochrome Adventure: The Monochrome Epic, 1960 — yvesklein.com

This exhibition marked the beginning of what Klein would call his “blue period.” The paintings did not represent anything. They were fields of colour intended to provoke a contemplative experience. For the artist, blue was not simply a pictorial tool but a mental place, a spiritual space.

“The viewer moved from one to another and instantly entered a state of contemplation within the worlds of blue.” Yves Klein, The Monochrome Adventure: The Monochrome Epic, 1960 — yvesklein.com

Ultimately, for Klein, blue was not merely another pigment. It was a conceptual territory from which the idea of the infinite could be explored, an idea born from his meditations beneath the blue sky of the Mediterranean.

The intensity of the Klein blue sought was not easy to preserve on canvas. Ultramarine pigment, when mixed with traditional paint binders, loses much of its characteristic luminosity. The result becomes a flatter, less vibrant blue. For an artist obsessed with the purity of colour, this posed a fundamental problem.

For this reason, in the late 1950s Klein began experimenting with different methods to preserve the pigment’s intensity. In Paris he met Édouard Adam, a colour merchant from the Montparnasse district. Together they worked on a solution: a synthetic resin called Rhodopas M, produced by the company Rhône-Poulenc. This new binder allowed the pigment to adhere to the surface without altering its original brilliance.

The result was precisely what Klein had been searching for: a deep, matte and intensely saturated blue. The surface appeared to absorb light, creating a hypnotic sense of depth. Klein applied the pigment with a roller to avoid visible brushstrokes, reinforcing the idea that colour should exist on its own, free from the interference of the artist. In this sense, the artist acted more as a messenger than as an intervening hand.

On 19 May 1960, Klein officially registered the process at the French National Institute of Industrial Property under the name International Klein Blue (IKB). It was not the patenting of a colour itself, which remains legally impossible even today. Institutions such as Pantone register intellectual property linked to colour systems or nomenclatures, not to pigments themselves. What Yves Klein patented was the technique that preserved the colour’s intensity.

From that moment onward, IKB became central to much of his work. Klein used it in sculptures, sponges, balloons and even performances. In his famous Anthropometries, for example, models covered in blue pigment pressed their painted bodies onto the canvas while the artist directed the action like a choreographer. Colour ceased to be a tool, what had once been a medium became the end itself.

Klein’s visual language also influenced postwar conceptual art. His monochromatic works proposed an idea aligned with the avant-garde: painting could be reduced to a single chromatic experience. Rather than representing the world, art could offer a space for contemplation and perception.

Over time, this aesthetic extended beyond the art world. Klein blue began to appear in graphic design, architecture, cinema and even contemporary literature. Its intensity made it instantly recognisable, a visual sign that evokes an entire conceptual trajectory.