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Thread: CSS Transparent Background and 1.4.3?

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From: Jim Homme
Date: Mon, Jan 23 2017 11:28AM
Subject: CSS Transparent Background and 1.4.3?
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Hi,
According to what I just read, transparent is the default if a CSS background color isn't coded by the developer. Since I'm totally blind,, how does that affect testing for 1.4.3, contrast? For instance, are the results different for black text on a white background, specifically coded, than they are if the developer just specifies black text and allows the default to take over?

Thanks.

Jim
=========Jim Homme,
Team Lead and Accessibility Consultant,
Bender HighTest Accessibility Team
Bender Consulting Services, Inc.,
412-787-8567,
= EMAIL ADDRESS REMOVED =
http://www.benderconsult.com/our%20services/hightest-accessible-technology-solutions
E+R=O

From: JP Jamous
Date: Mon, Jan 23 2017 11:42AM
Subject: Re: CSS Transparent Background and 1.4.3?
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Jim,

If you run the WAVE or Axe toolbars, they will catch this as the ratio would not be 4.5:1.

As far as transparent, I think the background would be the same as the operating system's background. Although I could be wrong about this one.

-----Original Message-----
From: WebAIM-Forum [mailto: = EMAIL ADDRESS REMOVED = ] On Behalf Of Jim Homme
Sent: Monday, January 23, 2017 12:28 PM
To: WebAIM Discussion List < = EMAIL ADDRESS REMOVED = >
Subject: [WebAIM] CSS Transparent Background and 1.4.3?

Hi,
According to what I just read, transparent is the default if a CSS background color isn't coded by the developer. Since I'm totally blind,, how does that affect testing for 1.4.3, contrast? For instance, are the results different for black text on a white background, specifically coded, than they are if the developer just specifies black text and allows the default to take over?

Thanks.

Jim
=========Jim Homme,
Team Lead and Accessibility Consultant,
Bender HighTest Accessibility Team
Bender Consulting Services, Inc.,
412-787-8567,
= EMAIL ADDRESS REMOVED =
http://www.benderconsult.com/our%20services/hightest-accessible-technology-solutions
E+R=O

From: Patrick H. Lauke
Date: Mon, Jan 23 2017 5:19PM
Subject: Re: CSS Transparent Background and 1.4.3?
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On 23/01/2017 18:28, Jim Homme wrote:
> Hi, According to what I just read, transparent is the default if a
> CSS background color isn't coded by the developer. Since I'm totally
> blind,, how does that affect testing for 1.4.3, contrast? For
> instance, are the results different for black text on a white
> background, specifically coded, than they are if the developer just
> specifies black text and allows the default to take over?

Assuming you mean a developer doesn't set explicit background color
anywhere, including the body/html elements:

- browsers used to default to a medium/light grey colour as the default;
however, most (all?) browsers these days default to a white default for
the body/html

- users *may* have specified that their browser should use specific
custom default colours. For this reason, not specifying at least an
explicit colour for the body/html elements in addition to a foreground
colour would lead to the explicitly defined foreground colour being
displayed over any kind of colour - making this impossible to test for
conclusively since it will depend on the user's settings (unless your
evaluation explicitly mentions that the result is only valid for default
browser values).

P
--
Patrick H. Lauke

www.splintered.co.uk | https://github.com/patrickhlauke
http://flickr.com/photos/redux/ | http://redux.deviantart.com
twitter: @patrick_h_lauke | skype: patrick_h_lauke

From: Jim Homme
Date: Tue, Jan 24 2017 10:17AM
Subject: Re: CSS Transparent Background and 1.4.3?
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Hi,
From the below, I'm translating that the test is inclusive, and that to ensure a valid test, we should advise the developer to code an explicit background color. Is that accurate?

Thanks.

Jim


=========Jim Homme,
Team Lead and Accessibility Consultant,
Bender HighTest Accessibility Team
Bender Consulting Services, Inc.,
412-787-8567,
= EMAIL ADDRESS REMOVED =
http://www.benderconsult.com/our%20services/hightest-accessible-technology-solutions
E+R=O

-----Original Message-----
From: WebAIM-Forum [mailto: = EMAIL ADDRESS REMOVED = ] On Behalf Of Patrick H. Lauke
Sent: Monday, January 23, 2017 7:19 PM
To: = EMAIL ADDRESS REMOVED =
Subject: Re: [WebAIM] CSS Transparent Background and 1.4.3?

On 23/01/2017 18:28, Jim Homme wrote:
> Hi, According to what I just read, transparent is the default if a CSS
> background color isn't coded by the developer. Since I'm totally
> blind,, how does that affect testing for 1.4.3, contrast? For
> instance, are the results different for black text on a white
> background, specifically coded, than they are if the developer just
> specifies black text and allows the default to take over?

Assuming you mean a developer doesn't set explicit background color anywhere, including the body/html elements:

- browsers used to default to a medium/light grey colour as the default; however, most (all?) browsers these days default to a white default for the body/html

- users *may* have specified that their browser should use specific custom default colours. For this reason, not specifying at least an explicit colour for the body/html elements in addition to a foreground colour would lead to the explicitly defined foreground colour being displayed over any kind of colour - making this impossible to test for conclusively since it will depend on the user's settings (unless your evaluation explicitly mentions that the result is only valid for default browser values).

P
--
Patrick H. Lauke

www.splintered.co.uk | https://github.com/patrickhlauke http://flickr.com/photos/redux/ | http://redux.deviantart.com
twitter: @patrick_h_lauke | skype: patrick_h_lauke

From: Moore,Michael (Accessibility) (HHSC)
Date: Tue, Jan 24 2017 10:38AM
Subject: Re: CSS Transparent Background and 1.4.3?
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It's like my first CS prof used to tell me. If you are not in control who is. Programming the colors eliminates surprises.

Mike Moore
EIR (Electronic Information Resources) Accessibility Coordinator
Texas Health and Human Services Commission
Civil Rights Office
(512) 438-3431 (Office)

Making electronic information and services accessible to people with disabilities is everyone's job. I am here to help.

-----Original Message-----
From: WebAIM-Forum [mailto: = EMAIL ADDRESS REMOVED = ] On Behalf Of Jim Homme
Sent: Tuesday, January 24, 2017 11:18 AM
To: WebAIM Discussion List < = EMAIL ADDRESS REMOVED = >
Subject: Re: [WebAIM] CSS Transparent Background and 1.4.3?

Hi,
From the below, I'm translating that the test is inclusive, and that to ensure a valid test, we should advise the developer to code an explicit background color. Is that accurate?

Thanks.

Jim


=========Jim Homme,
Team Lead and Accessibility Consultant,
Bender HighTest Accessibility Team
Bender Consulting Services, Inc.,
412-787-8567,
= EMAIL ADDRESS REMOVED =
http://www.benderconsult.com/our%20services/hightest-accessible-technology-solutions
E+R=O

-----Original Message-----
From: WebAIM-Forum [mailto: = EMAIL ADDRESS REMOVED = ] On Behalf Of Patrick H. Lauke
Sent: Monday, January 23, 2017 7:19 PM
To: = EMAIL ADDRESS REMOVED =
Subject: Re: [WebAIM] CSS Transparent Background and 1.4.3?

On 23/01/2017 18:28, Jim Homme wrote:
> Hi, According to what I just read, transparent is the default if a CSS
> background color isn't coded by the developer. Since I'm totally
> blind,, how does that affect testing for 1.4.3, contrast? For
> instance, are the results different for black text on a white
> background, specifically coded, than they are if the developer just
> specifies black text and allows the default to take over?

Assuming you mean a developer doesn't set explicit background color anywhere, including the body/html elements:

- browsers used to default to a medium/light grey colour as the default; however, most (all?) browsers these days default to a white default for the body/html

- users *may* have specified that their browser should use specific custom default colours. For this reason, not specifying at least an explicit colour for the body/html elements in addition to a foreground colour would lead to the explicitly defined foreground colour being displayed over any kind of colour - making this impossible to test for conclusively since it will depend on the user's settings (unless your evaluation explicitly mentions that the result is only valid for default browser values).

P
--
Patrick H. Lauke

www.splintered.co.uk | https://github.com/patrickhlauke http://flickr.com/photos/redux/ | http://redux.deviantart.com
twitter: @patrick_h_lauke | skype: patrick_h_lauke

From: Jonathan Avila
Date: Tue, Jan 24 2017 11:47AM
Subject: Re: CSS Transparent Background and 1.4.3?
← Previous message | No next message

> - users *may* have specified that their browser should use specific custom default colours. For this reason, not specifying at least an explicit colour for the body/html elements in addition to a foreground colour would lead to the explicitly defined foreground colour being displayed over any kind of colour - making this impossible to test for conclusively since it will depend on the user's settings (unless your evaluation explicitly mentions that the result is only valid for default browser values).

This is why we have F24: Failure of Success Criterion 1.4.3, 1.4.6 and 1.4.8 due to specifying foreground colors without specifying background colors or vice versa (https://www.w3.org/TR/UNDERSTANDING-WCAG20/visual-audio-contrast-contrast.html)

Jonathan

Jonathan Avila
Chief Accessibility Officer
SSB BART Group 
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703.637.8957 (Office)

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-----Original Message-----
From: WebAIM-Forum [mailto: = EMAIL ADDRESS REMOVED = ] On Behalf Of Patrick H. Lauke
Sent: Monday, January 23, 2017 7:19 PM
To: = EMAIL ADDRESS REMOVED =
Subject: Re: [WebAIM] CSS Transparent Background and 1.4.3?

On 23/01/2017 18:28, Jim Homme wrote:
> Hi, According to what I just read, transparent is the default if a CSS
> background color isn't coded by the developer. Since I'm totally
> blind,, how does that affect testing for 1.4.3, contrast? For
> instance, are the results different for black text on a white
> background, specifically coded, than they are if the developer just
> specifies black text and allows the default to take over?

Assuming you mean a developer doesn't set explicit background color anywhere, including the body/html elements:

- browsers used to default to a medium/light grey colour as the default; however, most (all?) browsers these days default to a white default for the body/html

- users *may* have specified that their browser should use specific custom default colours. For this reason, not specifying at least an explicit colour for the body/html elements in addition to a foreground colour would lead to the explicitly defined foreground colour being displayed over any kind of colour - making this impossible to test for conclusively since it will depend on the user's settings (unless your evaluation explicitly mentions that the result is only valid for default browser values).

P
--
Patrick H. Lauke

www.splintered.co.uk | https://github.com/patrickhlauke http://flickr.com/photos/redux/ | http://redux.deviantart.com
twitter: @patrick_h_lauke | skype: patrick_h_lauke