Color Revolution? Scientists Reveal Secret Hue Hidden from Human Eyes

Imagine seeing a color no human has ever seen before. That’s exactly what a group of researchers from the University of California and the University of Washington claim to have done in a groundbreaking study published in Science Advances.

By firing laser pulses directly into their eyes and stimulating highly specific cone cells in the retina, the scientists say they perceived a new color that's not found anywhere in the natural world. They’re calling it “olo,” and describe it as a hyper-saturated blue-green unlike anything in the visible spectrum.

“It’s more saturated than any color you can see in the real world,” said Prof. Ren Ng, co-author of the study and one of the five test subjects. “Let’s say you go your whole life seeing only pastel pinks, and one day you’re shown intense red. That’s what seeing olo was like.”

The experiment involved a device dubbed “Oz,” which uses mirrors, lasers, and optical components to selectively stimulate individual M-cones in the retina—cells that normally respond to green wavelengths. Typically, when M-cones are activated, they overlap with signals from neighboring S- (blue) and L- (red) cones, resulting in a blend of familiar colors. But in this tightly controlled setup, researchers isolated the M-cones, triggering a visual signal the human brain has never previously received.

Four of the five participants were men, and three were involved in writing the study. All had normal color vision. Participants matched the perceived “olo” using a digital dial to record the hue.

Despite the excitement, not everyone is convinced, according to a BBC report. Prof. John Barbur, a vision scientist at City St George’s, University of London, cautioned that the findings, while a technological achievement, are still “open to argument.”

Even Prof. Ng acknowledges olo isn’t likely to show up on your next trip to the paint store. “It’s very technically difficult to perceive,” he said. Still, the implications could be big especially for color blindness research.

For now, olo remains a rare, lab-born phenomenon. It's a glimpse at what our eyes might be capable of with just a little scientific magic.