"Fancy a little D.I.Y?"

Colour Blindness Simulator

Approximately one in twenty people have some form of colour blindess that prevents them from seeing colour the same way that people without any colour vision deficiencies do.

Many images and resources on the web are coloured in such a way that it's difficult for users with vision deficiencies to comprehend them. We've seen many examples in our time, including theatre seating plans where colour blind users couldn't differentiate one section of seating from another!

There are a number of colour blindness conditions, including the three simulated by our tool.

  • People with protanopia lack the long-wavelength sensitive retinal cones that are required to distinguish between colors in the green-yellow-red section of the spectrum.
  • People with dueteranopia lack medium-wavelength retinal cones and are therefore also unable to distinguish between colors in the green-yellow-red section of the spectrum.
  • People with colour blindness involving the inactivation of the short-wavelength sensitive cone system have tritanopia, a very rare blue-yellow colour blindness.

Use our Colour Blindness Simulator to reveal how your images may appear to users with a variety of colour blindness conditions. Upload a JPEG image of no more than 1000 pixels x 1000 pixels (100 KB filesize or less) to see how colour blind users may see it.

Want to upload a larger image or see how a website looks?


About our Colour Blindness Simulator

This is a new tool and therefore remains a work in progress. We'd appreciate your comments, good or bad. Contact us to tell us what you think.

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