Colorsmith

two paint chips, nearly the same. which is lighter?

pick the lighter or the darker of two near-identical paint chips; the gap closes until it finds your lightness threshold

The two chips are one hue and differ only in lightness. Each right answer brings the next pair closer and each miss moves it apart, so the gap settles where you are right about 7 times in 10. That gap is your lightness threshold, in ΔL* (CIELAB lightness, 0 black to 100 white), measured from the colours your screen was sent. A coin would be right 5 times in 10.

Concepts: color.

An interactive you play with one thumb, on Wundr.