Researchers in the United States have found a new color that no one has previously seen. This vivid blue-green shade is called “olo.” Scientists observed it during an experiment using laser pulses to stimulate the retina in a unique way. The study, published in Science Advances, involved five people with normal vision. Researchers used specialized equipment to target the retina’s M-cone cells, which sense medium wavelengths of light. This stimulation does not occur in everyday life, leading to perceptions unlike anything participants had seen before. Professor Ren Ng from UC Berkeley, a co-author and participant, described the experience as transformative. He compared it to seeing a bright red after only knowing pale pink. Although “olo” cannot be found in the natural world, the discovery raises intriguing questions about how we perceive color. Some experts suggest that “olo” might not be a true new color but a unique response from the brain. Nevertheless, this research offers important insights into human vision. It could eventually lead to advancements in treatments for color blindness. For now, “olo” remains invisible to the public, shining a light on untapped areas of our visual spectrum.