The color perception test shows a grid of color squares. Click the one that looks slightly different from the rest. Difficulty increases each round. 10 rounds total. Note: Not a medical color blindness test.
Which square is a different color?
Color Perception Score
This is not a medical test. For formal color vision assessment, consult an optometrist or use the Ishihara plates test.
How Color Vision Works
Normal human color vision relies on three types of cone cells in the retina, each sensitive to different wavelengths: short (blue), medium (green), and long (red). The brain combines signals from all three to perceive millions of distinct colors.
Color deficiency types
Red-green color deficiency (most common, 8% of men) makes it difficult to distinguish reds and greens. Blue-yellow deficiency (deuteranomaly/tritanomaly) affects blue-yellow discrimination. Complete color blindness (achromatopsia) is rare and results in seeing only black, white, and gray. Most color-deficient individuals don't lack a color entirely — they just see a reduced range in that axis.
Frequently Asked Questions
Is this color test free?
Yes, completely free with no signup required.
Is this a color blindness test?
No — this is a color discrimination test, not a medical color blindness assessment. For formal color vision testing, use the Ishihara test (available online) or visit an optometrist. If you find this test very difficult, particularly with red-green combinations, that may suggest color vision deficiency, but only a formal test can confirm.
What causes color blindness?
Color vision deficiency affects about 8% of men and 0.5% of women. The most common type (red-green color blindness) is a genetic condition where cone cells in the retina don't work correctly. Most people with color blindness see colors but have difficulty distinguishing certain color pairs, particularly red/green or blue/yellow.
What score indicates normal color vision?
8-10 correct out of 10 is typical for people with normal color vision. Difficulty in specific rounds — particularly reds/greens or blues/yellows — may indicate color deficiency in that color axis. This test uses general color discrimination and isn't calibrated for clinical diagnosis.
How does this color test work?
Each round shows a grid of same-colored squares with one slightly different square. You click the square that looks different from the others. Difficulty increases each round as the color difference becomes more subtle. This tests your ability to discriminate between very similar hues.