The short answer: red looks olive, green looks tan, and pink turns grey. Colors do not disappear — they collapse together. Two things that looked different become one thing.
The Most Common Misconception
Almost everyone imagines color blindness as a subtraction: a world in greyscale, or a world with the reds simply removed. That is not what happens, and it is worth correcting because it makes the real experience harder to understand.
Color vision works by comparing the responses of three cone types. Take one away and you do not lose a color — you lose the ability to tell certain colors apart. The colors that remain are still vivid. There are just fewer distinct ones, because pairs that used to look different now land on the same perception.
Total absence of color — genuine greyscale vision, or achromatopsia — exists, but it is extraordinarily rare, on the order of 1 in 30,000. It is not what the roughly 1 in 12 men and 1 in 200 women with color vision deficiency experience.
Every Common Color, Simulated
Below is what happens to eight everyday colors under the three main types of color vision deficiency. Every value in this table is real output from our simulation engine, which implements the models used in vision science — Viénot 1999 for protanopia and deuteranopia, Brettel 1997 for tritanopia. The color names beside each swatch are what our color name identifier returns for that exact value, so nothing here is described from memory.
| Color | Deuteranopia | Protanopia | Tritanopia |
|---|---|---|---|
Red#E01B24 | #838304olive | #565627dark olive green | #E10949crimson |
Green#2EC27E | #A8A881tan | #B8B87Ddark khaki | #5AB6D3sky blue |
Orange#FF7800 | #AEAE00olive | #90900Bolive | #FF6C83salmon |
Yellow#F6D32D | #DEDE27gold | #D7D72Egold | #FFC5CBpink |
Blue#1C71D8 | #6161D8slate blue | #6B6BD8slate blue | #0081A0steel blue |
Purple#9141AC | #6161ABcornflower blue | #4F4FACslate blue | #855A5Edim gray |
Pink#FF80B0 | #B2B2ADdark gray | #9696B1slate gray | #FC8695pale violet red |
Brown#865E3C | #6C6C3Adark olive green | #64643Cdark olive green | #89595Frosy brown |
What the Table Actually Shows
Red and green both become yellowish
This is the finding that surprises people. For a deuteranope, red does not turn grey or brown — it turns olive, a dark yellow. Green turns tan, a light yellow-brown. Neither looks like the other exactly, but both have moved into the same yellowish family, and the gap that used to separate them has mostly closed.
That is why a red-green pair is such a reliable failure. It is not that one of them vanishes; it is that they converge. And notice that the two are still slightly different in the table. Side by side, in good light, at large size, a deuteranope may well tell them apart. Across a page, on a thin chart line, at a glance? No.
Pink is the quiet casualty
Pink collapses to dark grey under deuteranopia and slate grey under protanopia. Of everything in the table it is the color that loses the most identity, and it is almost never mentioned in guidance, because everyone is busy talking about red and green.
If you use pink to signal something — a highlight, a category, a state — assume a large share of your audience is seeing grey.
Blue and yellow barely move
Blue shifts from a bright dodger blue to a slate blue and stays unmistakably blue. Yellow stays gold under both red-green types. This is the practical reason blue and yellow are the workhorse pair of accessible design: for the ~99% of color vision deficiency that is red-green, both survive nearly intact.
Tritanopia breaks a completely different set
Look at the last column and the pattern inverts. Red stays crimson. Green becomes sky blue. Yellow becomes pink. The red-green pair that fails for everyone else is fine here, and the blue-yellow pair that everyone reaches for as the safe option is the one that fails.
Tritanopia is rare — roughly 1 in 10,000, and it affects men and women about equally, unlike the red-green types. But it is the axis that acquired conditions tend to affect, which means the affected group is not only people born with it.
Why Two People With “The Same” Diagnosis See Differently
Everything above models a dichromat — someone missing a cone type entirely. Most people with color vision deficiency are not dichromats. They are anomalous trichromats: all three cone types present, but one shifted in sensitivity, which compresses rather than removes a dimension of color.
Deuteranomaly alone accounts for the largest share of cases, and its severity varies continuously from barely noticeable to nearly indistinguishable from deuteranopia. So two people with the same label can have genuinely different experiences, and simulations like these show the severe end of the range rather than a universal truth.
There is also a question no simulation can answer. These images show what colors would look like to you if your cones responded like theirs. What someone experiences after a lifetime of their own vision — how they name colors, what they have learned to compensate with, what looks normal — is not recoverable from a matrix.
A caveat about this page. You are reading these swatches on your own screen, which has its own calibration, in whatever light you happen to be in. The hex values are exact; how they land in your eye is not. The relationships between them — what converges with what — are the part to trust.
See It On Your Own Images
A table of swatches makes the mechanism clear, but the moment it becomes real is when you run something you made through it — your chart, your app, a photo of your own front door. Our color blindness simulator takes an image or your camera feed and applies the same models used to build the table above, across all eight vision types.
If you want to check a specific pair rather than a whole image, the color pair checker measures how far apart two colors stay under each type — and tells you whether a difference in lightness rescues them when the hue difference disappears.
Frequently Asked Questions
Do color blind people see in black and white?
Almost never. Complete absence of color vision, called achromatopsia, affects roughly 1 in 30,000 people. The common forms of color blindness leave color vision intact but reduce the number of distinguishable colors — reds and greens both drift toward yellow rather than disappearing.
What does red look like to a color blind person?
For a deuteranope, a strong red like #E01B24 simulates to #838304 — a dark olive. For a protanope it goes further toward #565627, a dark olive green, because protanopia also makes reds look darker. Red does not become grey or brown; it becomes a dark yellow.
Can color blind people see green?
Yes, but not as a distinct category from red in the way you might expect. A mid green simulates to a tan or khaki for both protanopes and deuteranopes. They see the color perfectly well — they just cannot reliably tell it apart from a red of similar lightness.
What colors can color blind people see best?
Blue and yellow. Both survive red-green color vision deficiency nearly intact, which is why blue-yellow is the standard safe pairing in accessible design. The exception is tritanopia, where blue-yellow is exactly the pair that fails and red-green is fine.
Do color blind people know what they are missing?
Usually not from the inside. Color vision is learned against your own experience, so a color blind person grows up calling a particular sensation "red" and it is simply what red is to them. Many find out only when they fail a school screening or a job test.
Is what I see in a simulation exactly what they see?
No, and this is worth being clear about. A simulation shows what a colour would look like to you if your cones responded like theirs. It models the optics, not the lifetime of perception built on top. It also models the severe end of the range — most people with color vision deficiency are anomalous trichromats with milder, highly variable effects.
See Your Own Images This Way
Upload a photo or use your camera to see any image through eight types of color vision deficiency, using the same models behind the table above.
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