He was still walking at random when the street went dark. He took four full seconds to think: power failure. The thrill of thunderstorms and ambulances came over him. He looked up; the sky was deep in stars. He'd forgotten how many there could be. Washes of them, spilling in streams. He'd forgotten how rich darkness looked. He could see, but poorly, without color, plunged into achromatopsia. Both of the achromats he'd interviewed had raged against the very words, red, yellow, blue. They lived for the night world, where they were superior to the color-sighted and merely ordinary. Weber fumbled in the dark for blocks, his sense of direction failing. When the lights surged back on, he felt the banality of sight.
--Richard Powers, The Echo Maker