Olo, a new color scientists say they've discovered: "It left us speechless."

A team of scientists from the University of California, Berkeley, has surprised the scientific community by claiming they have discovered a new, never-before-seen color , dubbed "olo," in reference to the binary code 010. This color does not exist in nature as perceived by the naked eye. It is described as a "greenish blue of unprecedented saturation" that can only be seen through laser stimulation.

Only five people in the world have been able to observe it thanks to a technique that allows us to go beyond the color range that a human can naturally perceive. Researchers call it the 'Oz—named after the Wizard of Oz—Vision System.' "The most saturated natural color pales in comparison," said Austin Roorda, a UC Berkeley researcher and one of the creators of Oz, when talking about olo.

Using an analogy, Berkeley electrical engineer Ren Ng, a co-author of the study, compared it to seeing "the most intense baby pink you've ever seen" after a lifetime of seeing only soft shades of pink. The results of the study, recently published in the journal Science Advances , describe the use of specialized lasers that can stimulate and control up to a thousand photoreceptors in the eye at once.

We have three types of cone cells in the eye: S, L, and M, and they're sensitive to different wavelengths. In the study, they describe that "any light that stimulates an M cone cell must also stimulate its neighboring L and/or S cones" because their function overlaps with theirs. But in this case, the laser only stimulated the M cones, "which in principle would send a color signal to the brain that never occurs in natural vision," the authors state.

They note that in this way, they precisely controlled the spatial distribution of light in the retina by applying microdoses of laser. "We predicted from the outset that it would appear to be an unprecedented chromatic signal, but we didn't know what the brain would do with it," Ng told the BBC. "It blew us away..." he added.

"We've created a system that can track, direct, and stimulate photoreceptor cells with such precision that we can now answer very basic, but also very intriguing, questions about the nature of human color vision," said James Carl Fong, the study's principal investigator. "It gives us a way to study the human retina at a new scale, something that's never been practically possible before," he added.

However, John Barbur, a vision scientist at City St George's University in London, questions the study's results and whether we're really talking about a new color. It's simply "a more saturated green produced by stimulating only the M cones," he told the BBC. Misha Corobyew of the University of Auckland comments that while single-cone stimulation has been achieved before, this time multiple cones have been precisely stimulated, and he acknowledges that this is groundbreaking.

Professor Ng emphasizes that OLO is "certainly very difficult to see technically," but the team's findings have the potential to help patients with vision impairments, such as colorblind people.

The research details that more ambitiously, Oz can be programmed to probe the plasticity of human color vision . “For example, gene therapy has been used to add a third type of cone in adult squirrel monkeys, producing trichromatic color vision behavior. In an analogous way, Oz can program signals to the human brain as if a subset of cones were filled with a new type of photopigment, allowing the qualitative experience of color to be explored —something that could not be revealed by the results of the squirrel monkey study,” they describe.

This approach allows for flexible exploration of neuronal plasticity to enhance the dimensionality of color in humans. " It's still a mystery whether, by expanding signals or generating new sensory inputs, the brain will be able to interpret and appreciate them? Well, I'd like to think so," Roorda said.