About the Color Blindness Simulator
Around one in twelve men and one in two hundred women have some colour vision deficiency, so a design that relies on colour alone can fail a significant audience. This tool simulates how a colour appears under the main types: protanopia and deuteranopia (red-green, the most common), tritanopia (blue-yellow), and achromatopsia (no colour). Each is shown as a swatch beside the original.
It is most useful for checking whether two colours you rely on to be distinguishable, a red error and a green success, for example, still differ for a colour-blind viewer. Where they do not, add a shape, label or icon so meaning does not depend on colour. The Grayscale Converter gives the no-colour view, and the Contrast Checker covers legibility.
How to use
- Enter a colour.
- Compare the simulated swatches with the original.
- If two important colours look alike, add a non-colour cue.
Common questions
- Which types are simulated?
- Protanopia and deuteranopia (red-green), tritanopia (blue-yellow) and achromatopsia (total colour blindness).
- How accurate is it?
- It uses standard simulation matrices, which approximate how these deficiencies shift colour. Real perception varies.
- What should I do if colours look the same?
- Do not rely on colour alone: add labels, icons or patterns so the meaning is still clear.