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Re: Color Contrast AA, and AAA

From: Benjamin Hawkes-Lewis <bhawkeslewis@googlemail.com>
Date: Sat, 08 Aug 2009 11:21:22 +0100
Message-ID: <4A7D51A2.9020701@googlemail.com>
To: W Reagan <wreagan1@yahoo.com>
CC: w3c-wai-ig@w3.org
On 08/08/2009 09:39, W Reagan wrote:
> Please read this statement below:
>
> *Instructions:* Select the situation below that matches your content.
> Each situation includes techniques or combinations of techniques that
> are known and documented to be sufficient for that situation.
>
>
>         Situation A: text is less than 18 point if not bold and less
>         than 14 point if bold
>
>    1.
>       G17: Ensuring that a contrast ratio of at least 7:1 exists between
>       text (and images of text) and background behind the text
>       <http://www.w3.org/TR/2008/NOTE-WCAG20-TECHS-20081211/G17>
>    2.
>       G148: Not specifying background color, not specifying text color,
>       and not using technology features that change those defaults
>       <http://www.w3.org/TR/2008/NOTE-WCAG20-TECHS-20081211/G148>
>    3.
>       G174: Providing a control with a sufficient contrast ratio that
>       allows users to switch to a presentation that uses sufficient
>       contrast <http://www.w3.org/TR/2008/NOTE-WCAG20-TECHS-20081211/G174>
>
>
>         Situation B: text is as least 18 point if not bold and at least
>         14 point if bold
>
>    1.
>       G18: Ensuring that a contrast ratio of at least 4.5:1 exists
>       between text (and images of text) and background behind the text
>       <http://www.w3.org/TR/2008/NOTE-WCAG20-TECHS-20081211/G18>
>    2.
>       G148: Not specifying background color, not specifying text color,
>       and not using technology features that change those defaults
>       <http://www.w3.org/TR/2008/NOTE-WCAG20-TECHS-20081211/G148>
>    3.
>       G174: Providing a control with a sufficient contrast ratio that
>       allows users to switch to a presentation that uses sufficient
>       contrast <http://www.w3.org/TR/2008/NOTE-WCAG20-TECHS-20081211/G174>
>
> My question is this: Does Color Contrast for AA, and AAA mean that I
> need to meet #1, #2 "AND" #3 must be met once I identified the font
> type, or does it mean, that "ANY" of the three techniques are sufficient
> to pass Color Contrast

1. Recall that the Understanding and Techniques documents are 
informative Notes, not Recommendations that impose conformance 
requirements. You could (in theory) find a solution that passes 1.4.3 
and 1.4.6 without following any of these techniques.

2. The text you quote isn't especially clear, but these techniques are 
meant to be alternatives.

--
Benjamin Hawkes-Lewis
Received on Saturday, 8 August 2009 10:22:04 GMT

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