We humans like to believe we’ve seen it all.
After all, the visible spectrum seems complete — sunsets, neon signs, high-definition screens.
But a group of scientists now claims we might be missing something. By using laser technology to stimulate single cone cells in the eye, they say they’ve generated a “never-before-seen” color called “Olo.”
This bold discovery is captivating experts and stirring controversy. Could the human brain perceive more colors than what we’ve known?
The claim is as bold as it sounds, raising wonder about the frontiers of the human mind, and a fair bit of controversy among experts.
The laser experiment that created ‘olo’
Researchers at the University of California, Berkeley, sought to see if they could “hack” the eye’s color receptors.
Normally, our retinas use three kinds of cone cells — S, M, and L — to process different wavelengths of light. These cones often work in combination.
For instance, we perceive a green leaf because it stimulates not just the M (green) cones but also a bit of the L (red) or S (blue) cones in subtle ways.
In nature, these cones always work in combination – for example, a teal leaf reflects light that triggers both M and S cones, blending into the blue-green we recognize. Crucially, there is no natural light that stimulates only the M (green-sensitive) cones by themselves.
This means the brain never gets a “pure” green signal unmingled with some red or blue.
But what if you could isolate just one cone type?
To do this, they mapped out tiny regions of each participant’s retina to find M-cone cells, and then used a special laser-based device (nicknamed “Oz,” a nod to the Emerald City) to hit those cells one by one with light.
By compensating for any eye movement and firing ultra-targeted laser flashes, they managed to stimulate only the M cones – something ordinary light could never do.
The result, reported in the journal Science Advances, was a “patch of color” in the person’s vision about twice the size of a full moon.
The researchers had essentially created a new visual signal in the brain: a color sensation produced by M-cone activation alone, unmixed with any other signal.
In honor of this binary novelty, they named the hue “Olo,” derived from the binary code 010 (meaning only the middle cone is “on”)
What does “olo” look like?
Describing Olo is tricky — by design, it’s beyond the standard visual palette.
Scientists claim it resembles a super-saturated teal or turquoise, except no real-world source of light can replicate it.
Screens and pigment mixes always blend signals from multiple cones — only direct laser stimulation of one cone type is believed to produce this color.
The small group who witnessed Olo — mostly the researchers and a few volunteers — were asked to match it using a digital color wheel. None could find an equivalent. Some described it as “pure green plus something extra.” Others simply said, “I’ve never seen anything like it.”
According to team member Ren Ng, no photo or screen can reproduce it. This underscores the impossibility of capturing Olo with standard technology.
Is it really “new”?
Some experts remain unconvinced. Skeptics note that “Olo” still falls within greenish territory — just an artificially extreme version. Since color is a product of the brain, critics question whether it’s truly a new hue or just “pure green.”
A vision researcher told the BBC that calling it new is “open to argument,” since all color perception is interpretive.
Still, the Berkeley team contends that no natural light exclusively stimulates only M cones, so the experience surpasses any green we can normally perceive.
It’s not about discovering a new wavelength, but about unlocking a novel combination that the brain can generate only under these lab conditions.
Even if the color is an “extreme green,” the fact that we’ve never encountered it in the wild is significant, suggesting the eye has hidden potential.
“Super green” once imagined
Interestingly, evolutionary biologist Richard Dawkins hypothesized this exact scenario decades ago, describing a hypothetical “super green” if scientists ever managed to trigger just the green cones.
According to The Guardian, Dawkins joked that it’s satisfying to see speculation become reality, as the research team effectively turned theory into practice.
Why Olo matters—for science and for us
Beyond the gee-whiz factor of “new color discovered!”, why does Olo matter?
For scientists, this experiment is a proof of concept that could open new avenues in vision research. By showing that the brain can experience colors beyond the natural input range, the team has effectively built a tool for probing the neural mechanics of sight.
The device “Oz” and the methods used to isolate single-cone responses might help researchers study how color vision works in unprecedented detail.
One practical angle is studying color blindness.
If scientists can craft stimuli that selectively activate certain cone types, they might test or simulate conditions for individuals missing a particular cone.
There’s also potential to explore other visual disorders where some cells malfunction or degenerate, offering new insights into how the brain compensates.
More broadly, it’s a proof-of-concept for pushing the boundaries of visual perception. By isolating single-cone responses, we can learn more about how the brain processes color.
Could there be “ultra-red” or “ultra-blue” experiences if we laser-target the other cone types?
Researchers say such ideas aren’t far-fetched, though the laser method is tricky, requiring extremely precise alignment and safety measures.
For now, it’s unlikely we’ll see “Olo TVs” — technology generally blends RGB signals, which can’t isolate a single cone. But the principle that we can create entirely new visual sensations by hacking the retina could one day have far-reaching implications, from artistic expression to medical therapies.
Controversies and critiques
Not everyone is sold.
Critics argue that calling it a “never-before-seen color” oversimplifies the neuroscience.
They fear sensational headlines overshadow the careful language scientists use, which emphasizes it as a color the human eye can’t reach under normal conditions, rather than a brand-new wavelength.
After all, nobody discovered a new frequency of light —this is purely an artifact of selectively activating the M cones.
Additionally, the very definition of color might need rethinking.
Is color about the wavelength hitting the retina, or the subjective experience in our minds?
The Berkeley team sides with the experiential view, highlighting that the mind’s reaction to unique stimulation can produce a phenomenon the participant perceives as distinct from any known shade.
For them, Olo represents a major leap, if only for a small group who dared to point lasers at their eyes.
Final thought: The hidden possibilities
In many ways, “Olo” stands as a testament to how little we truly know about our own senses.
We assume everyday life shows us the full picture. But science showed us once again that we can push the edges of perception and uncover sensations that break our mental boundaries.
What if the next breakthrough reveals not just a color, but a new dimension of experience in hearing, smell, or even taste?
However sensational it may sound, the discovery of Olo hints that reality might still have plenty of secrets —waiting, perhaps, for the next bold experiment to bring them to light.
