Colour Blindness Simulator
See how any colour or small palette might appear to someone with red-green or blue-yellow colour vision deficiency, so you can design artwork and products that work for more people.
Choose a Colour
Try a red and a green together to see why they are often hard to tell apart for people with red-green colour blindness.
Simulated Appearance
How to Use This Tool
Pick a colour with the colour picker or type in a hex code. The tool instantly shows five versions of that colour: the original, and how it would typically appear under protanopia, deuteranopia, tritanopia and full achromatopsia (complete colour blindness). Try comparing a red and a green swatch side by side to see how similar they can look under red-green colour vision deficiency.
The Main Types of Colour Vision Deficiency
Protanopia and deuteranopia both affect the ability to distinguish red and green and together make up the large majority of colour vision deficiency, mostly in men. Tritanopia, which affects blue-yellow discrimination, is much rarer. Achromatopsia, or complete colour blindness, is very rare and shown here mainly for reference.
Example
A vivid red (around #D32020) and a mid-green (around #4CAF50) look clearly different to most people, but under simulated deuteranopia they can shift towards similar muted yellow-brown tones, which is why red and green alone are a risky choice for charts, labels or safety information.
Designing with This in Mind
When colour needs to carry meaning, such as in a chart, a warning label, or a kit’s difficulty rating, try pairing colour with a second cue like a shape, label, pattern or position, and check your palette here rather than relying on colour alone.
Frequently Asked Questions
What does this tool do?
It shows an approximate simulation of how a chosen colour might appear to someone with protanopia, deuteranopia, tritanopia or achromatopsia.
What is the most common type of colour blindness?
Red-green colour vision deficiency (protanopia and deuteranopia, along with milder forms) is by far the most common type, affecting a significant share of men in particular.
Is this simulation medically exact?
No. It uses a well-known simplified colour transformation model to give a helpful visual approximation, not a clinically precise simulation of any individual person’s vision.
Why should artists care about this?
If colour is used to convey important information, such as skill level, safety, or which piece goes where, checking how it looks under colour vision deficiency helps make sure everyone can use it.
What is achromatopsia?
Achromatopsia is a very rare condition involving little or no colour perception at all, effectively seeing the world in shades of grey.
How can I make my colour choices more accessible?
Pair colour with another cue such as a label, icon, pattern or position, and avoid relying on red versus green alone to communicate something important.
Does this tool store or upload my colours?
No. Everything runs directly in your browser and nothing is saved or sent anywhere.
Is this tool free to use?
Yes, this tool is completely free to use with no sign-up required.
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Explore Painting KitsThis simulation uses a widely published, simplified colour transformation model to give a general visual approximation of colour vision deficiency. It is an educational design aid, not a medical or diagnostic tool, and does not represent any specific individual’s actual vision.