Color Vision Test
This test is for entertainment, not medical screening, diagnosis, or treatment advice.
This test measures how small a difference in color your eyes can detect. You will see a grid of squares that all look the same color, except one is a slightly different hue.
Your job is to tap the square that stands out. Each time you are right, the difference shrinks, so it gets harder. Your score is the smallest gap, in degrees of hue, you could still spot.
Your past attempts
What the color vision test measures
This test measures your hue discrimination, the smallest change in color you can reliably notice. It is the visual cousin of a pitch test: instead of asking whether you can see color at all, it asks how finely you can tell two colors apart when they are almost the same. We hold saturation and brightness fixed and change only the hue, the position of a color around the wheel, measured in degrees. That mirrors how color scientists isolate hue in tools like the Farnsworth (1947) arrangement tests and the Munsell Color System, which spaces colors into ordered steps of hue, value and chroma. Each round, eight squares share one hue and a single square is shifted by a set number of degrees. When you find it, the gap narrows. Your score is the smallest gap you could still pick out, so a lower number means a finer eye. Two people who both pass a basic color test can still differ a lot here, because resolving a tiny difference is a sharper task than simply naming a color.
How your eye sees color
Color vision starts with the cones, the light-sensitive cells packed into the center of the retina. Most people have three kinds, tuned to long, medium and short wavelengths, roughly the reds, greens and blues. This is trichromacy, and it is why three numbers can describe almost any color on a screen. A single cone cannot report color on its own, because many different wavelengths can make it fire equally. The trick is comparison: the brain reads the difference between the three cone signals, not their raw levels. Those comparisons are organized into opponent channels, red against green and blue against yellow, which is why some color pairs feel like opposites and why a reddish green is impossible to imagine. Hue discrimination depends on how cleanly those channels separate two similar signals. Where the cone responses overlap most, the eye splits very fine differences; where they overlap less, the same step in degrees is harder to see. That uneven sensitivity is normal and is part of why color test results shift with the exact colors on screen.
Which factors affect it
Your screen and your lighting usually move the score more than your eyes do. A dim, uncalibrated or budget display flattens small hue differences, and a "vivid" picture mode, a blue-light filter or night shift all change what reaches you. Ambient light matters too: glare, a colored bulb or sunlight on the panel all distort color, which is why a fair test wants even, neutral lighting. Beyond the setup, real differences exist between people. Color vision deficiencies, most often the red-green types described by Birch (2012), shrink the range of hues someone can separate. Age plays a slow role as the lens yellows and blues get harder to split. Fatigue, some medications and even a recent bright light can nudge your sensitivity for a while. Take the test the same way each time to compare your own results honestly.
What your score means
Your score is the smallest hue gap, in degrees, you could still spot, so a lower number is a finer eye. Read these bands as approximate tiers drawn from the color vision literature, not exact population percentiles, which do not exist for this skill in a clean form.
- Under 2 degrees is exceptional hue sensitivity. Your eye separates very small shifts in tone, the kind of resolution prized in color-critical work.
- 2 to 5 degrees is very good, typical of a healthy young adult on a decent screen who is paying attention.
- 5 to 10 degrees is the typical, average range. Most people resolve a color difference right around here.
- 10 to 20 degrees is below average for this task. It often points to screen quality or room lighting rather than your eyes.
- Over 20 degrees usually says more about the conditions than the viewer. Screen quality, calibration, a color filter or poor lighting will all push the number up here, and a result this coarse says little on its own. Try again on a calibrated screen in good light.
The tiers come from the color vision literature (Farnsworth 1947; Hardy, Rand and Rittler 1954; Birch 2012) and the Munsell hue spacing, framed as approximate ranges rather than precise percentiles. A single run is only a snapshot, so keep your honest best rather than a distracted first try.
Questions
I am not colorblind, so why did I score low?
The most common reason is the screen, not your eyes. A dim or uncalibrated display, a cheap panel, a blue-light filter, or night mode all flatten the small hue differences this test depends on. Bright sunlight or a glare on the screen does the same. The test shows colors with CSS, so it can only be as accurate as the device showing them. If you scored lower than you expected, turn off any color filter, set the brightness to a comfortable level, sit in even lighting, and try again.
Is there a difference between men and women?
Yes, on average. The most common color vision deficiencies are red-green types, and the genes for the red and green cones sit on the X chromosome. Men have one X, so a single altered copy affects them, while women have two and a working copy on either one usually covers it. The result is that red-green deficiency affects roughly one in twelve men but only about one in two hundred women. This is a population average, not a rule about any individual, so your own score is what matters here.
Does the type of screen matter?
It matters a lot. OLED panels show deeper, more saturated color and tend to separate hues cleanly, while older or budget LCD panels can wash subtle differences out, especially at the edges of the screen or off-angle. Color temperature settings, "vivid" or "eco" picture modes, and any blue-light filter all shift what you see. Two people with identical eyes can post different scores purely because of their displays. For the fairest comparison, take the test on the same device each time, with picture enhancements and filters switched off.
How does color vision change with age?
It drifts slowly over the years. The lens of the eye yellows with age, which absorbs more short-wavelength light and makes blues and violets harder to separate, so older adults often find the blue-yellow part of the spectrum trickier than the red-green part. The change is gradual and varies a lot from person to person, and good lighting helps at any age. This test sits in the midrange of hue where the effect is gentler, so a careful older viewer on a good screen can still resolve very small differences.
Can this test diagnose color blindness?
No. This is a fun benchmark, not a clinical screen. Real color vision testing uses standardized tools under controlled lighting, such as the Ishihara plates, the Hardy, Rand and Rittler plates, or the Farnsworth arrangement tests, all printed and lit to a fixed standard. This test runs in your browser on whatever screen and lighting you have, which is exactly the thing a clinical test controls for. If you are curious about your color vision for a real reason, a driving role or a design job, see an optometrist. Do not read anything medical into a browser game.
What is the most common type of color blindness?
Red-green deficiency, by a wide margin. It comes in a few forms depending on which cone is affected or missing, the green-cone types (deutan) and the red-cone types (protan), and together they account for the large majority of cases. People with a red-green deficiency do not see the world in grey: they confuse certain reds, greens, browns and oranges that most people separate easily. Blue-yellow deficiency exists but is far rarer, and total absence of color, seeing only in shades of grey, is rarer still.