A breakthrough in visual perception reveals an unseen color
In a striking scientific breakthrough, researchers have identified a previously unknown color that cannot be observed under natural conditions. The new hue, which they’ve named ‘olo’, was reported in a study published Friday (April 18) in Science Advances. The discovery, which pushes the boundaries of human perception, is being hailed as a major milestone in visual neuroscience.
According to scientists, the color can only be perceived when specific retinal cells are stimulated using a laser, a method that effectively overrides the limitations of the eye’s natural functionality.
Only five people have seen the color so far, and they describe it as something akin to peacock blue or teal, yet with an extraordinary degree of saturation that cannot be replicated on screens or in print.
Laser technology unlocks color beyond natural perception
To achieve the perception of olo, researchers fired carefully calibrated laser pulses into the retina, targeting individual cones—the light-sensitive cells responsible for color vision. The laser manipulation effectively bypasses the normal light processing pathways and pushes visual experience into a completely unfamiliar domain.
“We predicted from the beginning that it would look like an unprecedented colour signal but we didn’t know what the brain would do with it. It was jaw-dropping. It’s incredibly saturated,” said Ren Ng, an electrical engineer at the University of California, Berkeley.
The researchers shared a digital image of a turquoise square to approximate the color for public understanding, but emphasized that even high-quality reproductions fall short of capturing its full richness.
Scientists emphasize the uniqueness of the experience
“There is no way to convey that color in an article or on a monitor. The whole point is that this is not the color we see; it’s just not. The color we see is a version of it, but it absolutely pales by comparison with the experience of olo,” said Austin Roorda, a vision scientist who worked on the study.
The process of seeing olo involves isolating and stimulating M cones—the color-sensitive retinal cells tuned to medium wavelengths, typically not activated alone under natural lighting. Researchers first mapped the volunteers’ retinas to locate these M cones, then delivered laser flashes directly to them, allowing the brain to interpret the input in a new and extraordinary way.
Don’t expect to see ‘olo’ in daily life—or on your screen
Despite the excitement around the discovery, scientists are quick to note that olo is not about to enter consumer technology or everyday visual experiences.
“We’re not going to see olo on any smartphone displays or any TVs anytime soon. And this is very, very far beyond VR headset technology,” the researchers stated.
Understanding human vision and its boundaries
The human eye contains three types of cone cells—L (long wavelength, red), M (medium wavelength, green), and S (short wavelength, blue). Natural light typically stimulates a mix of these cones to produce the range of colors we perceive. However, no natural light selectively stimulates only M cones, making the perception of olo impossible without artificial intervention.
This discovery not only expands our understanding of color theory and human perception but also raises profound questions about the limits of what we can see—and what might lie just beyond those limits.
