Reverse Color Blind Test

Some plates hide numbers that are easier to see with red-green color blindness. Take the test, then compare with a friend who has different color vision.

What number do you see?

Each plate hides a number made of colored dots. Type the number you see, or tap “I can’t see a number”.

10 plates · about 1 minute · type a number only if you’re fairly sure

For accurate results

Turn screen brightness up and switch off Night Shift, True Tone, Night Light, blue-light filters and any color-adjusting apps or extensions.
Use a phone, tablet or monitor in normal indoor light, not in direct sunlight.
Wear your usual glasses or contacts, but not tinted or color-correcting lenses.
Don’t zoom in or stare. Answer with your first impression within a few seconds.

Keyboard: 0–9 type the number · Enter next · Backspace delete · N or Esc can’t see a number

How the reverse plates work

Each hidden-figure plate is filled with dots that vary strongly in red-green color. That noise only varies the color signal of one cone type. People who lack that cone type don’t see the noise. The number is drawn with a difference that is balanced to look equally bright to normal color vision, but brighter to someone without that cone type.

Why can color blind people see the hidden number?

Think of the number as being written in a faint light-and-dark difference, then covered with loud red-green camouflage. With typical color vision, the camouflage is what you notice and the number gets lost in it. If your red- or green-sensitive cones are missing or weaker, the camouflage fades, and the faint light-and-dark number is left standing out. It’s the opposite of a normal plate, where typical vision sees the number and color blind vision doesn’t.

Are reverse color blind tests real?

The effect is real and follows from how cones work, but reverse tests are much less reliable than standard plates. How well the camouflage hides the number depends on your screen’s colors and brightness, so results vary from device to device. That’s why this test mixes six hidden-figure plates with two standard red-green plates and two control plates that everyone should see.

Reading your result

You saw most hidden figures and missed the standard plates: this pattern fits red-green color blindness. Take the red-green test to estimate the type and severity.
You saw few or no hidden figures and passed the standard plates: the usual pattern for typical color vision.
Anything in between: common on this test, and often caused by the screen. Try the main color blind test for a clearer answer.

This is a fun experiment rather than a screening tool: results depend heavily on your screen. For a proper check, take the main color blind test.

Note: this is a screening, not a diagnosis. Online tests can’t control your screen’s colors or brightness, so confirm any result with an eye care professional. Medical disclaimer · How the test works

More color vision tests

Color blind testFull screening: red-green and blue-yellow, with type and severity.Red-green color blind testDeeper check for protan and deutan types.Tritanopia testBlue-yellow (tritan) color vision screening.Color blind test for kidsShapes instead of numbers, for children who can’t read digits yet.Color blind simulatorSee any photo the way people with color blindness see it.

Frequently asked questions

What is a reverse color blind test?

A reverse color blind test uses “hidden figure” plates: numbers that people with red-green color blindness can often see more easily than people with normal color vision. It flips the usual test around.

How can color blind people see something others can’t?

The number is camouflaged with strong red-green color noise. Normal color vision sees the noise, which hides the number. People who lack red- or green-sensitive cones can’t see that noise, so the number stands out as a difference in lightness.

I have normal color vision but saw some numbers. Is that wrong?

No. Hidden-figure plates are less reliable than standard plates, and on some screens people with normal vision can make out the numbers. That’s why this test also includes standard plates and why we recommend the main test for screening.

Does the reverse color blind test show the answers?

Yes, after you finish. Our plates are generated fresh each time, so there is no fixed answer key to look up, but the results page shows every plate next to your answer.

Can a reverse test tell me if I’m color blind?

Not on its own. Seeing the hidden numbers fits red-green color blindness, but some people with typical vision see them too. Use the standard plates in our main color blind test or red-green test for screening.