How to play
A color fills the screen for a set time (5, 3 or 1.5 seconds, your choice) and disappears. Then you rebuild it with three sliders.
- Hue: where the color sits on the rainbow, like red, yellow, green or blue.
- Saturation: how vivid it is. Zero is gray.
- Brightness: zero is black and 100 is the brightest version of the color.
Scoring
The gap between two colors is measured with CIEDE2000 (ΔE00), the color difference formula from the International Commission on Illumination (CIE). It weighs lightness, chroma and hue differences so the result tracks what people actually perceive, and a value of about 1 is often treated as a barely noticeable difference. Each round scores 10 ÷ (1 + (ΔE ÷ 12)^1.6): a ΔE of 3 earns about 9, 6 earns about 7.5, and 12 earns 5.
Tips for remembering colors
- Name the color, like "washed-out sky blue" or "deep brick red". Words stick.
- Set the hue first, then brightness, then saturation.
- Colors look different next to other colors and at other brightness levels, so keep your screen brightness steady.
Daily colors
Daily mode picks its colors from the date, so everyone gets the same five colors on the same day. Compare scores with friends. Your first run of the day is saved as your daily result.