A team of scientists from the University of California shared an image of a square painted in a new color. Scientists emphasized that it can only be seen when the retina is stimulated with laser pulses.
According to the researchers, the laser pushes color perception beyond natural boundaries.
What did the scientists and participants of the study report?
Five volunteers who took part in the experiment said they saw a new color called “olo.” They described it as “a blue-green of unprecedented saturation,” but added that those words don’t fully capture the experience.
Professor Ren Eng, a co-author and participant in the study, said, “From the beginning, we anticipated that this would be an unprecedented color signal, but we didn’t know how the brain would respond to it. It was incredible, extraordinarily rich.”
Austin Rurda, a vision specialist on the research team, added, “It is impossible to convey this color in an article or on a monitor.”
However, not everyone shares the team’s optimism, the publication reported. The Daily Mail quoted Professor John Barbour, a vision expert at St. George’s Hospital in London, who called the finding of “limited value.”
“This is not a new color. It is a more saturated shade of green that can only be perceived by a person with a normal red-green chromatic mechanism when the only input signal comes from M-cones,” he said skeptically.
What were the team’s conclusions based on?
People perceive colors when light falls on sensitive cells in the retina called cones. There are three types of cones: those sensitive to long (L), medium (M), and short (S) wavelengths of light.
Natural light is a mixture of waves of different lengths that activate the cones. Red light typically stimulates L cones, while blue light stimulates S cones. However, no natural light stimulates M cones in isolation, since M cones are concentrated in the middle of the retina.
During the study, the researchers stimulated only the M cones. Thus, a “color signal that never occurs under natural vision” was sent to the brain, the scientists wrote in a report for the journal Science Advances.
As a result, the participants saw a spot in the hue they called “olo,” which, according to the team, “does not exist in nature.”
