In a groundbreaking discovery, researchers at UC Berkeley have created a new color that exists outside the natural range of human vision - an intensely saturated blue-green hue dubbed "olo" that no one has ever seen before.
The breakthrough emerged from novel technology called "Oz" that allows scientists to precisely target and stimulate specific color-sensing cells in the human eye. This bypasses the natural limitations of human color perception.
"There's no wavelength in the world that can stimulate only one type of cone cell," explains Professor Ren Ng from Berkeley, who led the research. "We wanted to see what would happen if we could isolate and activate just the medium-wavelength cones."
The human eye contains three types of cone cells sensitive to different wavelengths of light - long (red), medium (green), and short (blue). Normally, these cells work together, with their sensitivities overlapping to create our perception of color. The Oz system uses adaptive optics and precise laser pulses to activate only medium-wavelength cones in isolation - something impossible under natural conditions.
In experiments with five participants, the team discovered that selective cone stimulation produced a vivid blue-green color unlike anything in nature. Professor Austin Roorda, one of the system's creators, described it as "a profoundly saturated teal" that made natural colors appear pale in comparison.
To verify that "olo" truly exists beyond normal human vision, participants attempted to match it using conventional light sources. They could only approximate it by adding white light to dilute the intensity - strong evidence that this color lies outside our natural visual range.
The current Oz prototype has limitations - it only works in a small area of peripheral vision and requires participants to maintain steady eye position. However, this research published in Science Advances represents a fundamental advance in vision science by demonstrating the ability to create entirely new visual experiences.
While some experts debate whether this constitutes a truly "new" color versus an intensified known hue, the achievement opens exciting possibilities for expanding human color perception and treating vision disorders in the future.
The research team continues working to enhance the technology's capabilities, potentially allowing larger visual coverage and free eye movement. For now, they have provided the first glimpse into a theoretical color space that was previously impossible for humans to experience.