W3C home > Mailing lists > Public > w3c-wai-gl@w3.org > April to June 2005

Re: Issue Summary 1.4

From: Tim Boland <frederick.boland@nist.gov>
Date: Wed, 08 Jun 2005 15:16:15 -0400
Message-Id: <>
To: w3c-wai-gl@w3.org

CSS2.1 defines the "color" value in [1], and also defines system color 
values in [2].
(NOTE: System colors are scheduled to be deprecated in CSS3 Color Module).
Are system colors included as "defined" (from excerpted text following), 
even though
they are scheduled for deprecation?

Thanks and best wishes
Tim Boland NIST

P.S.  Regarding Guideline 1.4 [3], are there unambiguous definitions of 
"foreground" and
"background" available for WCAG2.0, so that
one could clearly understand what is "foreground" and what is "background" 
relative to that
"foreground"?  WCAG2.0 WD glossary [4] has a definition for "background image"
(referring to "back of the
visual field?),  but not of "background" or "foreground" that I could 
find.   CSS2.1 describes
  the background of
an element as its "rendering surface".  I think it would be good to use 
similar terminology
(and similar definitions of such terminology) if appropriate and possible.

P.P.S   I'm also having difficulty parsing the wording of G1.4L1SC1 [3 
again].   Should this SC be written as "over a background image, background 
color, or background text.." (with a suitable definition for
"background" as mentioned previously), or is this what is implied by the 
current wording?   CSS2.1 has "background-image", "background-color", and 
"color" properties , but no "background-text" property.   The "color" 
property takes a "color" value (mentioned previously) or "inherit" (exactly 
one of them must occur), and the "background-color" property takes a 
"color" value, "transparent", or "inherit" (exactly one of them must occur) 
(please access [5] for more information).   Why does only "background-image"
in G1.4L1SC1 indicate a link to a definition?

[1]: http://www.w3.org/TR/CSS21/syndata.html#color-units
[2]: http://www.w3.org/TR/CSS21/ui.html#system-colors
[3]: http://www.w3.org/WAI/GL/WCAG20/WD-WCAG20-20050601/#visual-audio-contrast
[4]: http://www.w3.org/WAI/GL/WCAG20/WD-WCAG20-20050601/#glossary
[5]: http://www.w3.org/TR/CSS21/colors.html

   At 12:17 AM 6/8/2005 -0500, you wrote:

>ISSUE: 1372.
>  GL 1.4 - discourage background images
>Guideline 1.4 In visual presentations, make it easy to distinguish
>foreground words and images from the background.
>Should a distinction not be made between background colours (as defined in
>the html or CSS) and background images? Should foreground text over
>background images not be discouraged? Will the test for measuring the
>contrast take into account how people with different types of
>colour-blindness see?
>1 - yes - we have a stricter criterion for text over images.  But it is at
>level 3
>2 - Yes - test is structured so that it works across different types of
>color deficiency.
>No Change from current text.
>Close issue
Received on Wednesday, 8 June 2005 19:17:25 UTC

This archive was generated by hypermail 2.4.0 : Thursday, 24 March 2022 21:07:40 UTC