A Color Humans Were Never Meant to See
In a groundbreaking study led by scientists at the University of California, Berkeley, researchers claim to have discovered a previously unseen color named “Olo.” Unlike anything found in the natural world, this color cannot be observed with the naked eye. It is revealed only under an extremely specific condition: when targeted laser light stimulates a particular type of cone cell in the human retina. The visual experience is described as a deep, highly saturated teal — richer and more intense than any shade found in nature.
What makes this discovery especially intriguing is the fact that the human visual system is not equipped to perceive “Olo” under ordinary circumstances. Human color vision depends on three types of cone cells in the retina: S (short-wavelength, blue), M (medium-wavelength, green), and L (long-wavelength, red). Normally, these cones respond to overlapping ranges of light wavelengths, meaning no cone is ever stimulated entirely on its own. However, the research team managed to isolate the stimulation of the M cones alone, producing a color signal that doesn’t occur in standard human perception.
How the Experiment Was Conducted
The scientists developed a high-precision laser setup capable of directing light to activate individual photoreceptor cells in the eye. Each pulse of light was targeted to stimulate just the M cones — bypassing the overlapping activation of the neighboring cones that normally occurs. Through this method, they were able to trigger a completely new color experience.
Five human participants were involved in the experiment, including several of the researchers themselves. Among them were specialists from both Berkeley and the University of Washington. Importantly, some participants were unaware of the study’s purpose to prevent any bias in reporting what they saw. Each subject attempted to match the mysterious hue using standard color tools and consistently arrived at tones close to teal, though none were able to exactly replicate what they had seen under laser exposure.
While the visible match was closest to a peacock-green or saturated teal, the researchers emphasized that Olo was distinctly more vivid than any conventional color — too intense to be reproduced by standard lighting or digital displays.
Implications for Science and Medicine
This discovery holds promise far beyond just identifying a new color. By using advanced optics to stimulate cone cells individually, scientists are now equipped with a tool that may revolutionize our understanding of how the brain processes color. The findings could pave the way for new technologies to help people with visual impairments, including certain forms of colorblindness.
The ability to target specific cone cells offers insights into how the loss or malfunction of these cells affects visual perception. This is particularly relevant in the study of retinal diseases that lead to reduced color sensitivity, heightened light sensitivity, or even blindness. The researchers also see potential in adapting this method for diagnostic purposes, allowing earlier detection of degenerative eye conditions.
Beyond the medical field, there are hopes that the underlying technology could be used to explore the limits of human visual perception, offering new ways to experience and manipulate color in digital environments like virtual reality.
What Comes Next?
Despite the excitement surrounding the discovery, not all experts are convinced that “Olo” constitutes a truly new color. Some vision scientists argue that it may simply be a more saturated version of green, visible only when the eye’s red-green balance is precisely disrupted. However, the unique stimulation method employed in the study ensures that Olo remains a singular phenomenon — not found anywhere in the natural world, nor easily replicated on any current screen or pigment.
While there are no immediate plans to create a crayon, paint, or screen displaying Olo, the research team is actively working to refine their laser technology. Their long-term goal is to create an ultra-precise visual interface that can display colors on a cone-by-cone basis, unlocking experiences the human eye has never had before.
In the eyes of the researchers, Olo represents not a final discovery, but a beginning — a gateway into understanding the true depth and complexity of human vision, and possibly, expanding it beyond what evolution ever intended.