The Color You've Never Seen Before: OLO

Did you ever imagine that there could be a new color introduced to the world? The scientists at University of Washington and the University of California, Berkeley, have discovered a new color seen by no human before. The color, "olo," is defined as a highly saturated blue-green, and its existence is redefining the boundaries of human color vision.

How Was Olo Discovered?

The discovery of olo was made possible through a pioneering technique involving precise laser stimulation of the retina. Human eyes perceive color through three types of cone cells—L (long, sensitive to red), M (medium, sensitive to green), and S (short, sensitive to blue). Under natural conditions, these cones are always stimulated in combination, which constrains the range of colors we can see.

Yet the researchers created a system, named the "Oz Vision System" (in honor of the Emerald City in The Wizard of Oz), employing high-powered lasers and retinal tracking to target the M cones individually. It is not possible with normal light, and with it, the five volunteers saw a color outside the standard human gamut.

What Does Olo Look Like?

Scientists say they have discovered a never-before-seen color called “olo” by using lasers to stimulate the human eye in a way natural light can’t.

It’s described as a “jaw-dropping” blue-green hue that can’t be recreated on screens. pic.twitter.com/TNJCekZrJ4

— Pop Base (@PopBase) April 21, 2025

Panel members used the word "highly saturated blue-green" to characterize olo as more intense and vivid than anything that exists in nature or appears on a digital screen. Seen against a background of neutral gray, olo was so highly saturated that participants had to combine it with white light in order to match up with any standard color, and even then they could only approximate a match on the extreme fringes of the visible spectrum.

"There is no way to convey that colour in an article or on a monitor. The whole point is that this is not the colour we see, it’s just not. The colour we see is a version of it, but it absolutely pales by comparison with the experience of olo."
— Austin Roorda, vision scientist

Why Is Olo Unique?

Olo is unique in the way that it is perceived. Unlike every other color, which occurs due to overlapping stimulation of cones, olo appears only when a single kind of cone (the M cone) is stimulated individually. This makes olo impossible to replicate using any normal method—no pigment, screen, or natural source of light can render it. Just five individuals, all participants in the experiment as researchers, have laid eyes on olo at all, and only in these particular lab conditions.

Implications for Science and Vision Research

Discovery of olo is more than fascinating—it may signal a new route to research about vision disorders, color blindness, and the essence of the functioning of the human brain. The ability to dismiss the conventional bounds of color sensation starts research on how brains respond to purely novel visual stimulations, in the process shedding new light into possible breakthroughs in visual prosthetics and displays.

In addition, the development also gives the potential for developing new shades of color by altering single photoreceptors instead of just depending on mixing spectral colors.

A Glimpse Beyond the Rainbow

For the time being, olo is a scientific wonder—a miracle reserved for only a handful and a testament to how much can still be discovered about the perception of human beings. With advancement in technology, we can discover ways of letting more people have the experience of olo but for the meantime, it stands as proof that there are a thousand more options for scientific breakthroughs.