How to play the color matching game

Keep the target in view. Adjust Your mix, then press Submit color. A session contains three colors.

Choose your controls

Hue only: change hue from 0° to 360°. Saturation stays at 70% and lightness at 52%.
Full color: also change saturation and lightness from 0% to 100%. Saturation controls how far the color is from gray; lightness ranges from black to white.

Drag a slider, type a whole number, or use the − and + buttons. Tab moves among controls; arrow keys adjust a focused slider. Up and Down change a focused number by one. Enter or Space activates a focused button. You can complete every round without dragging.

Numeric help

Show target values reveals its H/S/L numbers. This gives a non-visual path: enter the same values in your mix and submit. Hint suggests one target value; Use suggested value applies it. An already identical RGB mix gets a Submit suggestion instead.

Using either help control marks that round as assisted. Undo and Restart keep this record because the target information has already been shown. Assistance does not change the score.

What the score measures

Both colors are converted to 8-bit sRGB numbers from 0 to 255. The score uses the ordinary distance between those three numbers:

distance = √((R₁ − R₂)² + (G₁ − G₂)² + (B₁ − B₂)²)
score = 100 × (1 − distance / (255 × √3))

Scores are rounded to two decimal places. Identical RGB values score 100. Black compared with white scores 0. The session average is the mean of its three submitted scores.

Hue 0° and 360° describe the same hue. When saturation is 0%, changing hue does not change the gray. At lightness 0% or 100%, many H/S/L combinations give the same black or white. These equivalent RGB colors count as exact matches.

This numeric score is not a measure of perceived color difference, a vision test or a medical assessment. How a color appears also depends on the display and viewing conditions.

Undo and continue

Submit ends a round, even if its score is low. Next color begins the next one. After three submissions, the summary reports the average and how many RGB matches were exact.

Undo reverses a numeric adjustment, submission or Next color action. A slider drag previews your mix, then saves one adjustment when you release it. Restart clears this session’s adjustments and results after confirmation, while keeping its assistance record.

Daily and saved progress

There are 24 original three-color sessions per control mode. Daily changes at 00:00 UTC and repeats every 24 days. Practice cycles through the same collection. Hue only and Full color each keep independent Daily and Practice progress.

An older daily remains open when you return. Play today asks before replacing an unfinished session. Switching to Practice resumes its existing session.

Progress stays in this browser. A failed save offers a retry. An unreadable record stays protected until you confirm Reset saved progress. If reading fails or another tab changes the saved record, reload to read the existing record first; the confirmation warns that temporary changes in this tab will be discarded.

Play Huewhorl