W3C home > Mailing lists > Public > w3c-wai-gl@w3.org > January to March 1999

Re: Colour blindness and web design

From: Chris Kreussling <CHRIS.KREUSSLING@ny.frb.org>
Date: Mon, 08 Mar 1999 17:20:09 -0500
To: w3c-wai-gl@w3.org
Message-id: <s6e406ec.015@ny.frb.org>
"Who needs color when real life is so black-and-white?" - postcard caption

I'm not aware of any "authoritative, credible source" on this topic. All I've ever found on this topic has been guidelines, the most important one being: 

Don't rely on color alone. Use redundant cues.

This takes it out of the realm of simply desiging a "colour scheme" to considering the readability of the content and usability of the site as a whole. Graphics designers come up with colour schemes; web designers have to undo the damage!

A quick test of whether a page makes sense when you can't distinguish colors: Print the page on a black-and-white/gray-scale printer. Even better: take the printout and copy it for two or three generations to see how it degrades. This will show you where you need to add redundant cues (example: hyperlinks are usually underlined on Web pages), or whether the cues are two small or indistinct to hold up well. And since I assume we're only considering the browser-safe palette, setup a colour scheme which uses just black, white and the four browser-safe greys and see how it holds up. It may be all you need.

For my part, I always do all of my presentations in black/white/gray, since I like to give copies to people attending and because I expect and hope they will make copies for their colleagues.

Two books I can recommend:

Jakob Nielsen, Usability Engineering
William Horton, Illustrating Computer Documentation (which includes chapters on online presentation issues)

<author>Chris Kreussling</author>
<disclaimer>The views expressed are 
those of the author and do not necessarily 
reflect the position of the Federal Reserve 
Bank of New York or the Federal Reserve 
System.</disclaimer>

>>> <w3c-wai-gl@w3.org> 03/08 4:07 PM >>>
In my capacity as Web Accessibility Auditor, a client has asked me to
prepare a 10-page report proposing a web design colour scheme readable
by people who are colour blind.  The report is to include:
 a section describing the 5 or 6 colour schemes for several home pages,
within a page layout to be provided by the client.  "Colour scheme"
includes the colours of the banner, navigation buttons, left sidebar
background, text and links.
 a section explaining how and why the standard was chosen.  This
rationale must be based on research, and derived from a method or an
authoritative, credible source.  The suitability of the colour schemes
for people who are colour blind must be based on more than subjective
opinion. 

Any credible information or contacts you can suggest would be greatly
appreciated.  As the report is due in approximately one week, time is of
the essence!

Thanks kindly,
Glenda

-- 
*********
Glenda Watson Hyatt
Communications Consultant
Soaring Eagle Communications
"Creating freedom and power through accessible communications"
E Mail: Glenda@eaglecom.bc.ca 
Website: http://www.eaglecom.bc.ca 

*********
Received on Monday, 8 March 1999 17:37:00 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Monday, 7 December 2009 10:46:59 GMT