The human eye perceives color using three types of cones, but no natural light can stimulate just the the cones associated with medium-wavelength light in the visible spectrum. The result, according to the authors, is a new color (which they’ve named “olo”) that’s kind of like a deeply saturated blue-green, but unlike any color a human has ever glimpsed before. The human eye is a wonder of evolution, and is our primary window into understanding the known universe that surrounds us. The human eye senses light and color thanks to the millions of rods and cones located in the retina. When mapped to the wavelengths in the visible spectrum, this roughly amounts to L cones interpreting the color red, S cones glimpsing blue, and M cones falling in the middle near an approximation of the color green.