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RE: Color Contrast

From: <gian@stanleymilford.com.au>
Date: Fri, 19 Apr 2002 16:12:11 +1000
Message-Id: <H00000e000449d1a.1019196730.tux.sofcom.com.au@MHS>
TO: uce@roserockdesign.com, w3c-wai-gl@w3.org
The success criteria:
Use a light grey or off-white instead of plain white as the background.
is likely to be a huge turn-off to developers. Could we include this,
but not make this success criteria part of the minimum set?
 
I believe that the disadvantages caused by this success criteria far
outweigh the benefits of making this part of the minimum set 
 
[I do realise that whether this was part of the minimum set has not been
discussed explicitly]
 
Gian

   -----Original Message-----
   From: uce [mailto:uce@roserockdesign.com]
   Sent: Tuesday, 16 April 2002 2:03 AM
   To: w3c-wai-gl
   Subject: Color Contrast
   
   

   

   Action LR: draft success criteria for contrast checkpoint.

   http://www.dai-sho.com/colorblindness/ 
   The most common color perception problems are with certain color
   combinations such as yellow on green, green on red, red on green,
   blue on red, red on blue, and red on black.

   The site above goes on to explain that using colors from the same end
   of the spectrum is difficult for people with colorblindness to tell
   the difference in the colors.  Additionally, light colors on dark
   colors are difficult to read as there is not enough area in the light
   areas to provide enough of a contrast.  Using varying shades of the
   same color also creates problems.

   If you intend on using red and green , make sure that when one
   changes to the other, that there is a suitable blinking, noise text
   or something to augment it. Please stay away from pastels, washed out
   colors, low intensity colors, and color combinations from the same
   part of the spectrum.

   http://www.lighthouse.org/color_contrast.htm 
   This site suggests using colors from opposite ends of the spectrum. 
   Additionally, it has several color charts that depict the difference
   in color spectrum and contrasting colors.  There is a great deal of
   information on the subject on this page.

   http://www.vischeck.com/vischeckURL.php3 
   An excellent resource for showing what the site will look like to
   someone that is colorblind.

   http://www.internettg.org/newsletter/mar99/color_challenged_applet.ht
   ml 
   This site has an applet that will show how colors look to the
   color-blind.

   http://www.msdn.microsoft.com/library/default.asp?url=/library/en-us/
   dn_voices_hess/html/hess10092000.asp?frame=true 
   Excellent color comparisons.

   Success Criteria:

   Achievement of color contrast will be based upon the following areas:
   1.  Text should be darker than the background.
   2.  Text and background will have sufficient contrast to distinguish
   the differences.
   3.  The saturation of colors will be sufficiently different to
   distinguish the differences.
   4.  The hue of the colors will be sufficiently different to
   distinguish the differences.
   5.  Color combinations of yellow on green, green on red, red on
   green, blue on red, red on blue, and red on black will not be used.
   6.  Use a light grey or off-white instead of plain white as the
   background.
   

    

   Sincerely,
   Lee Roberts
   Rose Rock Design, Inc.
   Building web sites accessible by EVERYONE
   http://www.roserockdesign.com
    

   
Received on Friday, 19 April 2002 02:13:18 GMT

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