Horizon blue
A blue-grey shade famous for French army uniforms in World War I
Horizon blue is a blue-grey colour, best known for its use in French army uniforms from 1915 to 1921. The name refers to the colour seen where the sky meets the earth and was used in fashion before it became a symbol of French soldiers in the Great War.
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- French army uniforms were horizon blue from 1915 to 1921
- The colour blends white, dark blue, and light blue wool
- First used in French fashion in 1884
- Fades and weathers unevenly in sunlight
- Still referenced in French military dress today
What colour is Horizon blue?
Horizon blue is a blue-grey colour, often described as the shade that appears where the sky meets the earth. It stands out from other blues by its soft, muted tone, which is neither fully blue nor grey. The colour became widely recognised because of its use in the uniforms of French soldiers during World War I, giving it a strong association with that era.
Where does Horizon blue come from?
The name 'horizon blue' was first used in French fashion in 1884 and later appeared in descriptions of paint and textiles. It was chosen for French army uniforms in 1914–1915, partly because blue was already a national colour and other neutral shades were used by foreign armies. The term became popular during the war, though it was never an official designation.
How Horizon blue is defined
Horizon blue cloth for uniforms was made by blending white wool (35%) with blue-indigo dyed wool (15% dark blue, 50% light blue). The process reused wool fibres already dyed for earlier uniforms, which helped production during wartime shortages. The colour did not hold up well to sunlight and weather, often fading unevenly.
Where Horizon blue is used
The most famous use of horizon blue was in French army uniforms from 1915 to 1921. It was also used in fashion before and after the war, and sometimes in painting and descriptions of eye colour. In the 21st century, it remains a reference in French military dress and literature.
What Horizon blue means
Horizon blue became a symbol of French soldiers, known as 'poilus', in World War I. After the war, it stood for ex-military men and was linked to strong nationalist politics in France. Its meaning is tied closely to French history and identity during and after the Great War.
Blue around the world
What the blue family means from country to country.
Blue was the colour of the French kings, whose arms were gold lilies on blue. It is the first band of the tricolour, and national sports teams are called Les Bleus.
Politics and protestRoyalty and powerPrideSource: Bleu de France (colour)Lapis lazuli has been mined in the mountains of Badakhshan for more than six thousand years. Ground to powder it gave ultramarine, the costliest blue in European painting.
Royalty and powerSacred and holyAweSource: Lapis lazuliThe chadari is a full-length covering for women with a mesh panel over the eyes. In Kabul and the north it is most often a light blue.
Protection and healingSource: BurqaThe blue band of the flag stands for the wish of the Armenian people to live under peaceful skies. The red above it is for the highlands and the struggle to survive.
Politics and protestHopeSource: Flag of ArmeniaThe flag is sky blue, white and sky blue, created by Manuel Belgrano in 1812. National teams are called the Albiceleste, the white and sky blue.
Politics and protestPrideSource: Flag of ArgentinaBoca Juniors play in blue and gold. The club's story is that in 1907 it took the colours of the flag of the next ship into port, which was Swedish.
Festival and celebrationPrideSource: Boca JuniorsShades and relatives of Horizon blue
Several tones of horizon blue have been described, including those shown in early 20th-century colour guides. It is sometimes called 'Imitation Cobalt Blue' and is related to other blue-grey shades like 'blued steel grey' and 'sky blue'.
Colours that go with Horizon blue
Harmonies are worked out from the value #7CA2B8. Contrast ratios follow the WCAG 2 formula.
Questions people ask about Horizon blue
What colour is horizon blue?
Horizon blue is a blue-grey shade, resembling the colour seen where the sky meets the earth. It is softer and lighter than navy or cobalt blue.
Why is it called horizon blue?
The name comes from the colour that appears at the horizon, where the sky meets the ground. It was first used in French fashion and later for army uniforms.
What is horizon blue best known for?
It is best known as the colour of French army uniforms during World War I, from 1915 to 1921.
How was horizon blue cloth made for uniforms?
The cloth was made by mixing white wool with blue-indigo dyed wool, using both dark and light blue fibres. This blend gave the fabric its distinctive blue-grey appearance.
Good reading and sources
The facts on this page come from the Wikipedia article "Horizon blue", written by its contributors and used under the CC BY-SA 4.0 licence, and from its Wikidata record (CC0). Rang rewrote the text in its own words, with AI assistance, and compares every page with the article to make sure no passage is copied. It may be reused under the same CC BY-SA 4.0 licence with a link back.
It may contain mistakes. The swatch is an approximation: named colours are not fixed standards, and every screen shows them a little differently. If something is wrong, tell us. Last refreshed 2026-10-03.
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