Thread Subject: Re: Contrast - Software

From: Peter Korn
Date: Wed, Jun 27 2007 6:35 PM

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Hi Sean,

I like where you are going with this.

But doesn't our existing, draft (and still to be hashed through by at
least the two of us, in an action item we were assigned some time back)
1194.21(g) address your second point - your application requirement? In
the latest draft I have (see the thread at:
http://teitac.org/mailarchives/mail_thread.php?thread=1125&id=4682#4682),
the text is: "Applications shall utilize the user selected contrast and
color selections and other individual display attributes defined by the
platform they are running on." We might expand that to say
"Applications shall have at least one mode in which they utilize the
user selected...".

Given our discussion earlier today about visual focus indication, we
might also expand/change this to: "... user selected contrast and color
selections, visual focus indication selection, and ..."


Regards,

Peter Korn
Accessibility Architect,
Sun Microsystems, Inc.

> To facilitate the discussion, I propose breaking this up a bit as:
>
> A platform requirement:
>
> "A platform product shall provide a setting to provide a contrast ratio of at least 7:1 for text or images of text; either based on an underlying platform setting, or if none such exists, by providing its own setting. This setting need not apply to text associated with unavailable user interface elements"
>
> -- we can separately discuss whether this setting gets baked in as a 'default' or not.
>
>
> And an application requirement:
> "When a product permits a user to adjust color and contrast settings, at
> least one selection shall be to use the contrast setting of the
> platform."
>
> -- again separately discussing whether this should be the default, and the setting used if no adjustment is permitted.
>
> Sean Hayes
> Standards and Policy Team
> Corporate Accessibility Group
> Microsoft
> Phone:
> mob +44 7977 455002
> office +44 117 9719730
>
>
> -----Original Message-----
> From: = EMAIL ADDRESS REMOVED = [mailto: = EMAIL ADDRESS REMOVED = ] On Behalf Of Peter Korn
> Sent: 27 June 2007 19:02
> To: TEITAC Web/Software Subcommittee
> Subject: Re: [teitac-websoftware] Contrast - Software
>
> Hi Andi,
>
> Coming out of our discussions in the meeting today, here is new
> suggested wording that addresses:
> a. limiting this to text
> b. excluding text in unavailable (e.g. "disabled") user interface elements
> c. text in images
> d. use of platform default
>
> "When a product permits a user to adjust color and contrast settings, at
> least one color selection capable of producing a minimum luminosity
> contrast ratio for text or images of text of 7:1 shall be provided.
> Default combinations of foreground and background colors (hue and
> luminance) should produce a minimum luminosity contrast ratio for text
> or images of text of 5:1, or should use the default settings of the
> platform. This does not apply to text associated with unavailable user
> interface elements."
>
>
> Regards,
>
> Peter Korn
> Accessibility Architect,
> Sun Microsystems, Inc.
>
>
>> For software, we currently have the following provision:
>>
>> When a product permits a user to adjust color and contrast settings, at
>> least one color selection capable of producing a minimum luminosity
>> contrast ratio of n:1 shall be provided. Default combinations of foreground
>> and background colours (hue and luminance) should produce a minimum
>> luminosity contrast ratio of n:1.
>>
>> We need to fill in the numbers for n:1. We said we wanted to harmonize this
>> with whatever we decided to do in Web.
>>
>> For Web, we hav the following provision which is harmonized with the WCAG
>> 2.0 level AA provision:
>>
>> Text (and images of text) have a contrast ratio of at least 5:1, except if
>> the text is pure decoration. Larger-scale text or images of text can have
>> a contrast ratio of 3:1.
>>
>> WCAG 2.0 also has a Level AAA provision that requires the contrast ratio to
>> be 7:1.
>>
>> I recommend that our software provision use 7:1 as the default required
>> contrast and require there be a color selection available to the user to
>> achieve the higher 5:1 contrast ratio. This would then result in the
>> following provision for software:
>>
>> When a product permits a user to adjust color and contrast settings, at
>> least one color selection capable of producing a minimum luminosity
>> contrast ratio of 5:1 shall be provided. Default combinations of foreground
>> and background colours (hue and luminance) should produce a minimum
>> luminosity contrast ratio of 7:1.
>>
>> Any objections?
>>
>> Andi
>>
>>

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