Colour blindness simulator

Question

Like any responsible developer, I'd like to make sure that the sites I produce are accessible to the widest possible audience, and that includes the significant fraction of the population with some form of colour blindness.

There are many websites which offer to filter a URL you feed it, either by rendering a picture or by filtering all content. However, both approaches seem to fail when rendering even moderately complex layouts, so I'd be interested in finding a client-side approach.

The ideal solution would be a system filter over the whole screen that can be used to test any program. The next best thing would be a browser plugin.

Answer 1

Here's a link to a website that simulates various kinds of color blindness:

http://www.vischeck.com/

They let you check URL's and Screenshots with three kinds of different color blindness types (URL checking is a bit dated though. Image-check works better).

I'd encourage everyone to check their applications btw. Seeing your own app with others eyes may be an eye opener (pun intended).

Answer 2

See this previous question:

http://stackoverflow.com/questions/87146/rgb-filters-for-different-forms-of-color-blindness

Answer 3

Here's an article that has some guidelines for optimizing UI for color blind users:

Particletree » Be Kind to the Color Blind

It contains a link to another article with the kind of tools you were asking for:

10 colour contrast checking tools to improve the accessibility of your design | 456 Berea Street

Answer 4

A great paper that explains a conversion that preserves color differences is:

Detail Preserving Reproduction of color images for Monochromats and Dichromats.(PDF)

I haven't implemented the filter, but I plan to when I have some more free time.

Answer 5

I came across Color Oracle and thought it might help. Here is the short description:

Color Oracle is a colorblindness simulator for Windows, Mac and Linux. It takes the guesswork out of designing for color blindness by showing you in real time what people with common color vision impairments will see.