Colour Vision Simulator
Simulate the eight forms of colour vision deficiency on your own screenshots, palettes and charts.
- Free
- Never leaves the browser
- No account
Processed on a canvas in your browser. Nothing is uploaded.
Simulate
Normal vision
6 colours
#C0300F
#33566B
#4A5A3C
#E0A800
#7A4E9B
#16150F
Deuteranomaly
#966100
#40526B
#56563D
#D2B10A
#5A5C9A
#16150F
Two swatches that converge here are two swatches your reader cannot tell apart. Give them a second signal — shape, label or lightness.
What the chat window cannot finish.
Around one in twelve men has some form of colour vision deficiency. This applies validated transform matrices to an image you drop in, so you can see which of your distinctions survive and which collapse.
This is pixel work. An assistant can describe what deuteranopia is; it cannot take your dashboard screenshot and show you that two of your chart series become the same colour.
The transform runs on a canvas in your browser. The image is never uploaded, which matters when the screenshot is of unreleased client work.
Prevalence
Approximate figures for populations of Northern European descent; rates vary by ancestry.
- Deuteranomaly
- ~5% of men — reduced green sensitivity, the most common form
- Protanomaly
- ~1% of men — reduced red sensitivity
- Deuteranopia
- ~1% of men — no green cone function
- Protanopia
- ~1% of men — no red cone function
- Tritanopia / tritanomaly
- ~0.01% — blue-yellow, affects all genders equally
- Achromatopsia
- ~0.003% — no colour discrimination at all
- Any form, men
- ~8%
- Any form, women
- ~0.5%
These constants are published under CC BY 4.0. Quote them, cite them, put them in your own documentation — attribution to Original Design Studio is the only condition.
The principles behind what this tool tells you.
Which type should I test against first?
Deuteranomaly. It is by far the most common, affecting around one in twenty men, and it is the one that breaks red/green status indicators.
My chart fails. What is the fix?
Add a second encoding. Direct labels on the series, distinct dash patterns or marker shapes, or a palette varied in lightness as well as hue. Redundant encoding costs little and helps everyone.
Is a simulation the same as lived experience?
No. These are approximations of the physiology and cannot represent how someone who has always seen this way actually perceives and compensates. Use it to catch obvious failures, then test with real people.
Next tool
06 — Type Scale
Want this run across your whole product?
An audit scores what you have shipped against all ten disciplines — tested with assistive technology and on real hardware — and returns a prioritised plan.