colour blindness

[Gorgon]

I use Web Designer 11 and have been experimenting with contrasting colours for lines, fills and backgrounds. I am now wondering how far these effects may be invisible or confusing to people with colour blindness (about 8% of men, apparently). Does anyone have experience of testing their pages against one of the colour blindness simulators that can be downloaded, or do people use other methods of ensuring maximum visibility, clarity and readability?

Thank you.

[gwpriester]

Interesting question. And I have absolutely no idea. If there are certain colors that are difficult then I would avoid those colors. Though color blindness does not necessarily mean the visitor cannot see a color, it is just that he or she might not be able to distinguish the color from another color.

[Egg Bramhill]

Yes, interesting question. The main problem I could see (excuse the pun) is that people aren't either colour blind or not colour blind. There's a large spectrum of colour blindness which would make it very difficult to produce a "colour-blind version" of an image.

[Acorn]

I've had to design sites for full accessibility issues over the years.
There are standards that you could follow but it would be a five-fold increase in design and test to meet most of these.

If you are only interested in visual diversity, these offer some advice and tools;

• http://www.w3.org/WAI/intro/people-u...versity#visual
• http://www.uxmatters.com/mt/archives...ent-vision.php

Acorn

[Gorgon]

Thanks for the replies, and to Acorn for the links. Here is an image from one of the diagnostic tests for colour blindness that might be of interest.

People with normal colour vision see a number 29 concealed in the array, but people with red-green colour blindness see a number 70.

[Acorn]

Thanks for the replies, and to Acorn for the links. Here is an image from one of the diagnostic tests for colour blindness that might be of interest.

People with normal colour vision see a number 29 concealed in the array, but people with red-green colour blindness see a number 70.

I remember this Ishihara test at my school over 55 years ago. I distinctly remember saying it was 29 but that if you looked closely you could also see 70!

Acorn