Color Blindness Simulator
See how a color appears under four types of color blindness.
Color Blindness Simulator
Color Blindness Simulator shows how a colour appears to viewers with protanopia, deuteranopia, tritanopia and achromatopsia, so you can check a palette against the most common forms of colour vision deficiency.
How to use it
- Pick a colour, or type a hex value.
- Compare the simulated versions side by side.
- Test the colours you rely on to carry meaning.
Which deficiencies matter most
Roughly 8% of men and 0.5% of women of Northern European descent have some colour vision deficiency. Deuteranopia and deuteranomaly, affecting green perception, are by far the most common. Protanopia affects red perception, and tritanopia, affecting blue, is rare.
The practical consequence is that red and green become hard to tell apart for a substantial share of your audience. Any interface using red for error and green for success, with no other distinguishing signal, is unreadable to them.
When it helps
- Checking whether a chart's series remain distinguishable.
- Testing a status colour scheme before shipping it.
- Choosing a palette that survives colour vision deficiency.
- Making the case for adding icons or labels alongside colour.
Common mistakes
- Using colour as the only way to convey meaning. Add a shape, an icon, a label or a pattern so the information survives.
- Assuming a red and green pair is fine because they look different to you.
- Testing only full deficiency. Anomalous trichromacy, a partial version, is more common than full dichromacy and shifts colours rather than removing them.
