Color Perception Test

• Where your blue begins: the hue where your answers switched from "green" to "blue". Hue is a color's angle on a color circle; we use the OKLCH color space, where equal steps in hue look about equally different. On our scale, green is near 140° and blue near 250°.
• The three swatches: a color a little greener than your boundary, the boundary itself, and a color a little bluer. A friend may call the middle one by the other name.
• Error score: how far the colors in your rows were from their right order. Each color scores the gap to its two neighbors, minus 2, so a row in perfect order scores 0. Lower is better.
• The ring: every color of the hue circle, in its own color. A longer spike means a bigger mix-up at that hue; "most mix-ups" names the region with the most.

Your boundary has no right or wrong answer. The error score does: 0 is perfect. Neither is a medical result.

1. Blue or green? One color appears at a time, on a neutral grey. Tap Green or Blue, or press ← and →. Go with your first impression.
2. Closing in. Two sequences of colors run at the same time, one starting near the green end and one near the blue end, 12 colors each. A "green" answer moves that sequence toward blue, a "blue" answer toward green, and the steps get smaller each time you change your mind. Both meet near your boundary.
3. Colors in order. Then you get 4 rows of 12 colors. Each row has a fixed color at both ends; drag the colors, or tap two to swap them, until the row changes smoothly. There is no clock.

All 52 colors of part 2 go once round the color circle, about 6.9° of hue apart, at the same lightness and colorfulness, so only the hue changes. Your answers and your final order are scored on our server: the boundary is the 50% point of a curve fitted to all your answers, and the error score follows the 100-hue test's rule. Results are saved to build fair comparisons, as our privacy policy explains.

• Your screen. Screens differ in color, brightness and settings. Night mode, blue-light filters, "true tone" and a dim screen all shift colors toward yellow. Even the maker of the clinical 100-hue test says an online version can't be definitive, because monitors vary [8]. Compare results on the same screen.
• The room. Bright or colored light around you changes how the screen looks.
• Your language. The words you use for colors shape where you put the line. Languages that name light and dark blue separately, or green and blue together, draw different boundaries [2][4][9].
• Age and tiredness. Color sorting gets harder with age [5], and tired eyes make close colors harder to sort.
• Color vision. People with a red-green color deficiency usually find some rows much harder. If parts of the test felt impossible, an eye doctor or optometrist can test your color vision properly.

The color perception test shows where you personally put the line between green and blue, and how finely you can order very similar colors on this screen. It is a game based on research tasks. It is not a color blindness test, not a medical test, and not the Farnsworth–Munsell test itself: its scores can't be compared with clinical norms. We are not affiliated with X-Rite or Munsell.

If you think you might be color-blind, an optometrist or eye doctor can test you with proper plates and lighting.