What is the Color Hue Test?
The Color Hue Test asks you to put colors back in order. Each strip holds 10 caps from one stretch of the color wheel; the two end caps stay fixed, and you drag the 8 between them into a smooth gradient. 4 strips cover the whole wheel, and your score counts how far your order is from the true one: 0 is perfect.
The 40 colors are equal steps of 9.0° round the wheel in OKLCH, a color space built so that equal steps look about equally different. Every cap has the same lightness (0.75) and colorfulness (chroma 0.12), so hue is the only thing that changes. The wheel starts at a random hue each game, so the strips are never the same twice.
How is the Color Hue Test score calculated?
Each cap scores how far its neighbors are from its true neighbors: the difference between its number and each neighbor's number, added, minus 2. A cap between its true neighbors scores 0, so a strip in order scores 0. Your score is the total over all 40 caps; the time you took is shown beside it but not scored.
This is the error score Dean Farnsworth published with his 100-hue test in 1943. It grows with how far a color strays, not just with how many are wrong, because a cap out of place also spoils its neighbors' scores. Some examples on one strip, worked out by the scoring code:
| One strip | Error score |
|---|---|
| Every cap in order | 0 |
| Two neighbors swapped | 4 |
| One cap three places from home | 12 |
| One cap from one end to the other | 28 |
| Left as dealt (shuffled), on average | 42 |
What can affect your Color Hue Test score?
Your screen matters as much as your eyes. Neighbouring caps differ by about 1.9 points of color difference (OKLab distance × 100; 1.7 to 2.1 once the screen's whole-number colors are rounded). That is a small difference, so anything that shifts the screen's colors shows up in the score.
- Night mode and blue-light filters tint every color warmer and squeeze the blues and purples together. Turn them off, and auto-brightness too, before you start.
- Viewing angle. Many laptop screens shift color when seen from above or below. Look at the strip straight on.
- Room light reflecting off the screen washes out the palest differences. A dim room is best.
- The screen itself. Phones and monitors show the same numbers as slightly different colors, so a score from one device doesn't carry over to another.
Is the Color Hue Test a color blindness test?
No. It borrows the format of a clinical test, but the clinical Farnsworth-Munsell 100 Hue Test uses 85 physical caps, painted to a standard and viewed under a daylight lamp, and its scores are compared with norms for each age. A screen's colors are uncalibrated, this version has 40 caps, and its scores aren't on the same scale. A high score here can mean a warm screen as easily as anything about your eyes. If you think your color vision has changed, see an optometrist.
Where does the hue test come from?
Dean Farnsworth described the 100-hue test and its scoring in 1943 (Journal of the Optical Society of America). Its strength is that it measures how finely you tell hues apart, all round the wheel, rather than only sorting people into color blind or not. To test the same eye in other ways, try the Color Difference Test, which shrinks the gap between two shades until you can no longer see it, or the Color Memory Test.