Close Hue

Close Hue asks a simple question: what does mauve actually look like? Each day it shows you five colour names, the same five for every player in the world, and you guess each colour with a picker. Some names are familiar, like Goldenrod or Chartreuse; others are obscure, like Coquelicot, Falu Red or Xanadu. The pool holds more than 6,000 names, gathered from a hand-made list, Wikipedia's list of colours, an open colour-name collection and the xkcd colour survey.

The picker uses three sliders, hue, saturation and brightness, rather than red, green and blue, which suits the way colour names describe things: a hue family, how vivid, how dark. There is no timer; only your final guess counts. When you submit, the real colour appears beside yours and you get a score. The site measures the gap with CIEDE2000, a standard formula for how different two colours look to the eye, and turns it into 0 to 100, so a near miss in a colour family still earns most of the points.

Five rounds make a daily total out of 500, and a whole game takes about three minutes. You can share a grid of coloured bands that does not give the colours away. Beyond the daily game there is an unlimited mode with random colours and a multiplayer mode where friends join a room with a six-letter code. Stats and streaks are kept on your device, and no account is needed.