Scientists Manipulate Eye Into Seeing New Color “Olo”

In a groundbreaking study, scientists at the University of California, Berkeley, have developed a technique called “Oz” that allows the human eye to perceive a brand-new color, which they have named “olo.” This color is described as a blue-green or teal of unprecedented saturation-far more vivid than any color found naturally or previously seen by humans.

The Oz system operates by using minuscule pulses of laser light to precisely stimulate specific photoreceptor cells, called cones, in the retina. Human color vision is based on three types of cones: S (short wavelength, blue-sensitive), M (medium wavelength, green-sensitive), and L (long wavelength, red-sensitive). Normally, the wavelengths that activate the M and L cones overlap significantly, meaning that any greenish light will stimulate both types of cones together. This overlap makes it impossible, under natural conditions, to activate only the M cones without also triggering the L cones.

To overcome this, the Oz platform first maps the unique arrangement of cone cells in each participant’s retina. Then, using highly targeted laser pulses, it can selectively stimulate up to 1,000 photoreceptors at once, focusing primarily on the M cones. By activating just these cones in a controlled area of the retina, the system tricks the brain into perceiving a color signal that does not occur in natural vision, resulting in the experience of “olo”.

Only five people, including some of the researchers themselves, have seen “olo.” Participants described the color as a “profoundly saturated teal” or “peacock green,” with a vibrancy surpassing even the most intense monochromatic colors like those from a green laser pointer. When the laser stimulation was slightly misaligned and other cones were inadvertently activated, the perception of “olo” disappeared instantly, replaced by the ordinary green of the laser. This stark contrast highlighted just how unique and striking the new color experience was.

The creation of “olo” is more than a novelty; it opens new avenues for vision science. The Oz technique provides an unprecedented level of control over retinal stimulation, allowing researchers to:

• Investigate fundamental questions about how the brain processes color.
• Simulate vision loss or cone cell degeneration in healthy subjects for research into eye diseases.
• Explore potential applications for color blindness, possibly enabling color-blind individuals to experience a broader spectrum of colors.
• Test the theoretical limits of human color perception, such as the possibility of simulating tetrachromatic vision (as if humans had a fourth type of cone cell).

While the discovery has been celebrated as a major leap in understanding human vision, some experts argue that “olo” is not a fundamentally new color in the physical sense, but rather a previously inaccessible perceptual experience. Since “olo” can only be seen using specialized laser technology and not through any natural light or on screens, it remains outside the realm of everyday human experience. Critics note that the color is essentially a hyper-saturated green that can only be perceived when the M cones are uniquely and exclusively stimulated, something not possible in nature.

The Oz technique and the discovery of “olo” represent a significant advance in both the science and philosophy of color perception. By expanding the boundaries of what the human eye can experience, the research not only dazzles with the promise of new colors but also provides a powerful tool for probing the mysteries of vision, brain function, and sensory experience. The work, funded by federal grants and detailed in Science Advances, marks a new chapter in the exploration of human perception.

More information is available here.

Image: James Carl Fong, doctoral student in electrical engineering and computer sciences (EECS) at UC Berkeley.

David Shiller

David Shiller is the Publisher of LightNOW, and President of Lighting Solution Development, a North American consulting firm providing business development services to advanced lighting manufacturers. The ALA awarded David the Pillar of the Industry Award. David has co-chaired ALA’s Engineering Committee since 2010. David established MaxLite’s OEM component sales into a multi-million dollar division. He invented GU24 lamps while leading ENERGY STAR lighting programs for the US EPA. David has been published in leading lighting publications, including LD+A, enLIGHTenment Magazine, LEDs Magazine, and more.

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