Colour Blindness Simulator
See how your colours and images look with protanopia, deuteranopia, tritanopia and achromatopsia.
Result
How to use
- 1
Type the colours of your design, chart or logo (or keep the sample).
- 2
Compare how they look for the four main types of colour blindness.
- 3
Optionally choose an image to see the whole picture simulated.
Questions
How common is colour blindness?
About 8% of men and 0.5% of women have some red–green colour vision deficiency. Studies in India find similar rates — so in a class of 40 boys, about three are likely to be colour blind.
How is the simulation calculated?
Colours are converted to linear RGB and multiplied by the Machado, Oliveira & Fernandes (2009) matrices for full-strength protanopia, deuteranopia and tritanopia. Achromatopsia uses the luminance (brightness) only.
How do I make designs colour-blind friendly?
Don’t rely on red vs green alone. Add labels, icons or patterns, use blue/orange pairs, and keep good lightness contrast between colours.
About this Colour Blindness tool
Colour Blindness Simulator — See how your colours and images look with protanopia, deuteranopia, tritanopia and achromatopsia. It is one of 200 free tools on namasivayam.in, made by software engineer Namasivayam Vadivelan for everyday use in India.
Everything is calculated instantly in your browser: nothing you type or upload is sent to any server, there is no sign-up, and it works on mobile and desktop. Type the colours of your design, chart or logo (or keep the sample).
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Results are estimates to help you plan. They are not financial, tax or medical advice.