Color Vision Test — Find the Odd Colour Online Free
Can you spot the odd colour? 10 rounds — each round the difference between colours gets smaller. Tests colour discrimination.
How to use this tool
- Look at the displayed circle pattern.
- Enter the number or shape you see.
- Work through all plates to see your results.
Find the circle that has a slightly different colour from all the others. 10 rounds — the difference gets smaller each round, making it harder.
How it works
Each round shows a 5×5 grid of circles, all the same hue except one. The hue difference starts large and decreases each round. This tests colour discrimination ability — the ability to distinguish subtly different hues. Percentile rankings are based on population averages for hue discrimination tasks.
About Color Vision Test
The Color Vision Test challenges your ability to distinguish subtly different hues. Each round displays a grid of twenty-five circles arranged five by five. Twenty-four of them share an identical color, and exactly one is a slightly different hue. Your task is to click the odd circle out. The test runs ten rounds, and your score is simply how many of the ten you identified correctly, with feedback after each click telling you whether you were right.
The challenge ramps up automatically. In the first round the odd circle differs from its neighbors by a clearly visible amount, but the hue difference shrinks with each successive round, narrowing toward roughly ten degrees of hue by the final plate. The exact base color, saturation, and lightness are randomized every round so you cannot memorize anything, and the odd circle's position is random too. A percentile ranks your total against population averages for this kind of hue-discrimination task, where the median is about 8 out of 10.
What the test measures is color discrimination: how finely your eyes and visual system can separate neighboring hues. The difficulty setting controls how large the difference starts, which sets the overall challenge curve. Easy begins with a generous gap of around 55 degrees, Medium starts near 40, and Hard opens at about 28 degrees, so even the early rounds demand careful looking. Screen quality, brightness, and ambient lighting all influence what you can perceive.
For your most accurate result, view the grid on a well-calibrated screen in even lighting and avoid glare or harsh reflections. Scanning systematically, row by row, rather than darting around helps you catch the subtle outlier, especially in the late rounds where the difference is smallest. Looking slightly to the side of the grid can sometimes make a faint odd circle pop out, since peripheral vision is sensitive to contrast. Note that this is an entertaining online test, not a medical diagnostic, so it cannot diagnose color blindness. Everything runs in your browser and no results leave your device.
Frequently Asked Questions
- Does this test diagnose color blindness?
- No. It is a fun online discrimination test, not a medical diagnostic. If you are concerned about your color vision, see an optometrist for a proper clinical examination such as an Ishihara plate test.
- How does scoring work?
- There are ten rounds, each worth one point. Your score is the number of rounds in which you correctly clicked the odd-colored circle, from 0 to 10, with the median result around 8.
- Why does each round get harder?
- The hue difference between the odd circle and the rest shrinks every round, narrowing toward about ten degrees of hue by the final plate. Later rounds therefore require much finer color discrimination.
- What do the difficulty levels change?
- They set how large the color difference is at the start. Easy begins around 55 degrees of hue, Medium around 40, and Hard around 28, making every round, including the first, more demanding on Hard.
- Does my screen affect my score?
- Yes. Display calibration, brightness, color accuracy, and your room's lighting all influence how easily you can spot subtle hue differences. A poorly calibrated or dim screen can lower your score.
- Why are the colors different every time I play?
- The base hue, saturation, and lightness are randomized each round, and the odd circle's position is random too. This keeps the test fresh and prevents memorizing answers.
- What types of color blindness exist?
- The most common is red-green deficiency, including deuteranopia and protanopia, affecting roughly eight percent of males. Blue-yellow deficiency, called tritanopia, is much rarer.
- Is my data sent anywhere?
- No. The test runs entirely in your browser and no results are transmitted.
Embed this tool on your site
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<iframe src="https://brevio.pro/embed/color-vision-test" width="100%" height="600" loading="lazy" style="border:1px solid #e5e5e5;border-radius:8px" title="Color Vision Test — brevio"></iframe> <p style="font:12px/1.4 sans-serif"><a href="https://brevio.pro/tools/color-vision-test">Color Vision Test</a> by <a href="https://brevio.pro">brevio</a></p>