Color surprises from the high-tech present and the ancient past

New hue! Who knew?It’s not every day that you get to see something no one in the world has seen before. But Ren Ng and four of his colleagues are lucky enough to have had that experience. Earlier this year, Ng sat down next to a laboratory table covered with a maze of lasers, lenses, mirrors, and other optical engineering gizmos. Then he let his fellow researchers focus a laser beam—eye-safe, worry not—into his dilated pupil. The University of California, Berkeley, electrical engineering and computer science professor was the second subject of an experimental system he and his colleagues designed to make the eye perceive an unnatural color. When weak laser pulses hit thousands of light-perceiving cone cells in his retina, a small green square the same color as the laser light slowly appeared in his vision. Gradually, as the team focused the laser more precisely, the color became more and more blue-green. “And at some point, as it really gets perfected, you're like ‘Wow,’” Ng tells Newscripts. The hypersaturated blue-green he experienced seeing is imperceptible to humans under natural circumstances. The searchers are calling the color “olo” (Sci. Adv. 2025, DOI: 10.1126/sciadv.adu1).Declaring olo the Pantone color of the year could be tough, given that people can’t see it without laser stimulation. That’s because of the way human eyes work. The eye has three types of cone cells. Each is sensitive to a spectrum of short (S), medium (M), or long (L) wavelengths. Those spectra overlap, and the middle M