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[Issue 317] Color

From: Gregg Vanderheiden <gv@trace.wisc.edu>
Date: Sun, 18 Apr 2004 20:44:02 -0500
Message-Id: <200404190144.i3J1i7ML027501@jalopy.cae.wisc.edu>
To: <w3c-wai-gl@w3.org>

Interesting comments.

Hmmmm

If the text is colored... then it by definition can be read by the User
Agent or it wouldn't be able to render it red.  

If the colored information is a line or something in a graphic - then it
would need to be described.   

All of this would give the information to someone who is blind and using a
screen reader or something designed to give color information to a person
who is using a screen reader.

But for a person who is colorblind -- they would generally only have
standard visual browsers.    And figuring out which item is what color based
on color codes in the source would be beyond them.  

Now
1- we COULD require all color blind people to have a plug in that would
expose colors to them.
OR 
2-  we COULD require authors to have something that would provide a
redundant non-color cue for any color encoded information.

Or we COULD rely on #1 for level 1 conformance (which would mean no specific
color requirements at level 1) and require #2 at level 2 or level 3. 

SIDE NOTE:  #2 would be required for the information to be accessible if it
were printed or displayed on a projector.   But we are talking web
guidelines here and not printed or displayed content.   So minimum necessary
to make the content accessible via a user agent (including AT) would be #1.


Anyone see holes in the above
- or additional things to keep in mind?
- or anything else on this?



 
Gregg

 -- ------------------------------ 
Gregg C Vanderheiden Ph.D. 
Professor - Ind. Engr. & BioMed Engr.
Director - Trace R & D Center 
University of Wisconsin-Madison 


-----Original Message-----
From: w3c-wai-gl-request@w3.org [mailto:w3c-wai-gl-request@w3.org] On Behalf
Of Marja-Riitta Koivunen
Sent: Sunday, April 18, 2004 6:20 AM
To: w3c-wai-gl@w3.org
Subject: Re: [Issue 317] Color


At 12:37 AM 4/18/2004 -0500, Gregg Vanderheiden wrote:

>I was assigned the color checkpoints to work on cleanup
>
>They currently read:
>
>LEVEL 1:  Success Criteria for Guideline 1.3
>Any information presented through color is also available without color
(for
>example through context or markup or coding that does not depend on color).
>@@issue 317?
>Note:
>
>Color must be interpretable by a user agent so that the user doesn't have
to
>look at markup to determine meaning.
>
>LEVEL 2:  Success Criteria for Guideline 1.3
>Information presented using color is also available without color and
>without having to interpret markup (for example through context or text
>coding). @@issue 317 [V]
>
>
>
>ISSUES
>- it is not clear what is meant by code.  It is supposed to mean that you
>mark the materials in a visual fashion that can be viewed without needed
>special user agent or feature.  But coding sounds a lot like markup.
>
>- level 1 should allow markup as solution.  Then level 2 would go further
>and make it directly accessible.
>
>
>POTENTIAL REWORDING
>
>LEVEL 1:  Success Criteria for Guideline 1.3
>Any information presented through color is also available without color
(for
>example through markup or context or characters or symbols that accompany
>the color coding) [I]
>
>Note:  If markup is used, markup must be interpretable by a user agent so
>that the user doesn't have to look at markup to determine meaning.

When I read this it is so abstract that I'm not at all sure what it means 
in practise? Not even sure if we are talking about visual presentation? I 
think user agent can interpret color differences better than a user who is 
color blind.

Maybe we should talk first about classifying visual information by using 
class attributes and other means of markup so that it be easily presented 
to the user in different ways.

If color is used for the differentiation, also some other visual coding is 
needed e.g. form, texture, labelling, proximity etc.


>LEVEL 2:  Success Criteria for Guideline 1.3
>Information presented using color is also available without color and
>without having to interpret markup (for example through context or or
>characters or symbols that accompany the color coding).   [V]
>
>Not sure what the difference here is to level 1? Maybe the classification 
>and use of stylesheets should be here and plain visual differentiation at 
>level 1?
>
>Gregg
>
>------------------------
>
>Gregg C Vanderheiden Ph.D.
>Professor - Depts of Ind. Engr. & BioMed Engr.
>Director - Trace R & D Center
>University of Wisconsin-Madison
><http://trace.wisc.edu/> FAX 608/262-8848
>For a list of our listserves http://trace.wisc.edu:8080/mailman/listinfo/
Received on Sunday, 18 April 2004 21:45:06 GMT

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