Thread Subject: Re: Contrast - Software

From: Sean Hayes
Date: Wed, Jun 27 2007 6:20 PM

• Return to this mailing list's archives
• View all messages in this thread
• Next message in thread: Peter Korn: "Re: Contrast - Software"
• Previous message in thread: Peter Korn: "Re: Contrast - Software"
• Messages sorted by: Author | Thread | Date

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
>
>

• Next message in Thread: Peter Korn: "Re: Contrast - Software"
• Previous message in Thread: Peter Korn: "Re: Contrast - Software"