Olo
An imaginary blue-green seen only by stimulating M cones in the retina
No single value: Olo is a material, and its colour varies. The background shows its family, turquoise and cyan.
Olo is a colour that cannot be seen under normal conditions and is produced by activating only the M cone cells in the human eye using lasers. Discovered in 2025 at UC Berkeley, it is described as an extremely saturated blue-green, with the closest sRGB match being #00FFCC.
- Olo can only be seen by stimulating M cones with lasers
- It was discovered at UC Berkeley in 2025
- Described as a blue-green of unprecedented saturation
- Closest sRGB match is #00FFCC
- Only five people have officially seen olo
What colour is Olo?
Olo is a colour that cannot be seen in everyday life. It is created by stimulating only the M (medium-wavelength) cone cells in the retina, without affecting the L (long-wavelength) or S (short-wavelength) cones. This makes it impossible to see olo through any natural light or pigment, as all visible light overlaps the sensitivities of these cones. Olo appears as a blue-green shade that is more saturated than any colour found in the natural world.
Where does Olo come from?
The name 'Olo' comes from the LMS colour space coordinates (0, 1, 0), which represent full activation of the M cone and none of the others. The colour was discovered by researchers at UC Berkeley in April 2025, who used adaptive optics and scanning laser ophthalmoscopy to target individual cone cells. Only five people have officially seen olo, all participants in the original experiment.
How is Olo made?
Olo is not made from any material or pigment. Instead, it is produced by mapping the retina and using lasers to deliver precise doses of light to M cone cells, while avoiding the L and S cones. This process uses advanced imaging and adaptive optics to ensure only the intended cells are activated, creating a colour experience outside the normal range of human vision.
Where Olo is used
Olo has not been used in art, design, or everyday life, as it cannot be reproduced with pigments or screens. Some artists have shown interest in creating paints inspired by olo, but the actual colour remains accessible only through specialised scientific equipment.
What Olo means
There are no traditional or cultural meanings attached to olo, as it is a newly discovered and artificially produced colour. Its main significance lies in scientific research, especially in understanding human colour perception and exploring possible applications for colour blindness and enhanced vision.
Turquoise around the world
What the turquoise and cyan family means from country to country.
The old colour word qing covers green, blue and the shades between. In the five-element system it belongs to wood, the east and spring.
Nature and renewalCalmSource: Blue–green distinction in languageTurquoise, firuzeh in Persian, has been mined near Nishapur for thousands of years. It is worn against the evil eye, and its colour covers the domes of mosques in Isfahan.
Protection and healingSacred and holyAweSource: TurquoiseIn the image of Our Lady of Guadalupe, Mary wears a blue-green cloak covered in stars. Turquoise was precious to the Aztecs, who used it in mosaic masks.
Sacred and holyAweSource: Our Lady of GuadalupeThe English word turquoise comes from the French for Turkish, because the stone reached Europe through Ottoman lands. Tiles from Iznik made the colour a mark of Ottoman mosques.
Royalty and powerSource: TurquoiseThe mosques and tombs of Samarkand are faced with turquoise and deep blue tiles. The three great madrasas of the Registan square and their ribbed turquoise domes are the best known.
Sacred and holyAweSource: RegistanShades and relatives of Olo
Olo is described as a blue-green with extreme saturation, unlike any colour seen in the real world. The closest colour in the sRGB colour space is #00FFCC, but this is only an approximation. Olo is unique in that it cannot be confused with any naturally occurring colour, as it exists outside the visible gamut.
Questions people ask about Olo
What colour is olo?
Olo is described as a blue-green shade with a level of saturation not found in the natural world. It is closest to the colour #00FFCC in the sRGB colour space, but cannot be seen under normal conditions.
How was olo discovered?
Olo was discovered in 2025 by scientists at UC Berkeley. They used lasers and adaptive optics to stimulate only the M cone cells in the retina, creating a colour experience outside the normal human visible range.
Where does the name 'olo' come from?
The name 'olo' is based on the LMS colour space coordinates (0, 1, 0), which means only the M cone is activated. The letters were used to form the name.
Can olo be seen in everyday life?
No, olo cannot be seen under normal viewing conditions. It requires specialised scientific equipment to stimulate only the M cones in the eye, which cannot be achieved with natural light or ordinary displays.
Has anyone seen olo?
Only the five participants in the original UC Berkeley experiment have officially seen olo, as it requires precise stimulation of the retina using lasers.
Good reading and sources
- Hue new? Scientists claim to have found colour no one has seen beforeThe Guardian, Article
- Scientists Say They've Discovered a New Color—an 'Unprecedented' Hue Only Ever Seen by Five PeopleSmithsonian Magazine, Article
- Scientists claim to have discovered 'new colour' no one has seen beforeBBC, Article
- Have scientists discovered a new colour called ‘olo’?Al Jazeera, Article
The facts on this page come from the Wikipedia article "Olo (color)", 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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