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How can I check if my user interface is suited for colorblind people?

I'd like to ensure that color blind users experience the UI with sufficient contrast between elements and similar aesthetics as other users. What are some good resources to help with this?


9 Answers 9


You may test this one:


Enter the URL for the web site you want to test, and select a color blindness type.
The tool will then show you the web site like the color blind user will see it.


Color Oracle works pretty nice. (Desktop application, works on all platforms)

It gives you simulations of the 3 different types of colorblindness. Good tool for quickly checking how the color blind would see your work.

  • The URL has moved, but this is a great app! Thanks for the tip. Here's the new URL: colororacle.org
    – Baronz
    Commented Feb 23, 2016 at 16:00

Another color blindness simulator is vischeck, it can be used online on images and on urls. I've also used sim daltonism (mac only).

Color blindness is not very rare (among men), chances are that you already know a colorblind person but never realised he was colorblind. They can tell you about compensation strategies, etc., things that a simulator can't know.

  • Thanks! Color Oracle seems to be very popular, but I'm not very fond of desktop java apps. Commented Feb 3, 2017 at 4:22

Colorblind Vision is an iPhone app for simulating colorblindness in realtime (30 fps).


I've heard that the most basic test would be to make a screen capture and convert to grayscale on an image editor and see if you can tell colors apart easily.

  • While it might work, only a very small percentage of the population have this full colour blindness. Most colour blindness is red/green where you have difficulty distinguishing just those two colours.
    – ChrisF
    Commented Aug 9, 2010 at 22:47
  • I think it's not aimed only at people with full color blindness. Certain tones of green and blue (or other) can be really similar in grayscale. Anyway, it's a very basic test.
    – Ignacio
    Commented Aug 9, 2010 at 23:08
  • 1
    When designing with color blindness in mind, one needs to think about the contrast between colors. A combination of red and green can be accessible as long as the contrast between the two is enough. Conversion to grayscale can help in determining contrast.
    – eBeth
    Commented Sep 3, 2011 at 19:31

Fuji has a little app for Windows. Colordoctor


Another vote for Colororacle, it covers the three main types of colour blindness,and it has a very nice implementation. The black and white test that ign mentions is also for colour in redundancy tests, and that is available on the web developer toolbar


There is also a Chrome extension called Daltonize https://chrome.google.com/webstore/detail/efeladnkafmoofnbagdbfaieabmejfcf


I reckon it really comes down to contrast as ign indicates.

Check out WCAG: Visual audio contrast They also list some tools for checking the contrast between colors.

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