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Does 1.4.1 cover differences in state?

From: Repsher, Stephen J <stephen.j.repsher@boeing.com>
Date: Thu, 16 Nov 2017 18:38:27 +0000
To: James Nurthen <james.nurthen@oracle.com>, "w3c-wai-gl@w3.org" <w3c-wai-gl@w3.org>
Message-ID: <ed1e1ad2933c4ef68c2c2e590cf544f6@XCH15-08-08.nw.nos.boeing.com>
Hi James,

The proposed Graphics Contrast SC does not attempt to cover differences in state, but I think this is an important question and I’m confused by your conflicting responses (or at least that’s how I perceive it).

Going back to your words at https://lists.w3.org/Archives/Public/w3c-wai-gl/2017OctDec/0436.html...

Mike: There is no language requiring a contrast minimum between the states themselves. I would really like that to at least be captured in the Understanding doc, if it can't be part of the SC, because being unable to differentiate between states is as much of a problem as not being able to differentiate between controls.

James: I always fail this on 1.4.1 Use of Color: Color is not used as the only visual means of conveying information, indicating an action, prompting a response, or distinguishing a visual element. (Level A)

James: If the ratio is 3:1 or greater then it is no longer color alone (hue and lightness) so no longer fails 1.4.1. As such I don’t think this needs to be in this SC.

So where is the misunderstanding occurring here?  Do you feel 1.4.1 applies to some state differences but not others?

I think this will be an important point to ultimately clarify in the respective Understanding docs for these SC.


From: James Nurthen [mailto:james.nurthen@oracle.com]
Sent: Thursday, November 16, 2017 11:32 AM
To: w3c-wai-gl@w3.org
Subject: Re: CFC - Graphics Contrast

No it would not. 1.4.1 does not mention the word state and include a definition which includes hover. Hover does not fit into the things which fail 1.4.1

Take for example the page https://www.w3.org/TR/UNDERSTANDING-WCAG20/visual-audio-contrast-without-color.html

There are contents, intro, Previous and Next buttons at the top of the page. The only difference when they are hovered is the background color.

The background color is #dde and the hover background color is #aae

The ratio between these is 1.6:1

I would not fail this page and I object to any SC which would fail this. My current reading of this new SC along with the definition of state proposed would and hence I object.

On 11/16/2017 7:54 AM, Repsher, Stephen J wrote:
Adding to what Alastair is saying, I’m confused by the objection because, as you pointed out, using color alone to differentiate between hover and non-hover would be a violation of 1.4.1.  Only when the 2 states are adjacent and touching would this SC come into play, but the 3:1 ratio requirement is the same.


From: Alastair Campbell [mailto:acampbell@nomensa.com]
Sent: Thursday, November 16, 2017 3:03 AM
To: James Nurthen <james.nurthen@oracle.com><mailto:james.nurthen@oracle.com>
Cc: WCAG <w3c-wai-gl@w3.org><mailto:w3c-wai-gl@w3.org>
Subject: RE: CFC - Graphics Contrast

> Requiring hover to have sufficient contrast ratio to non-hover states has no accessibility requirements behind it as far as I know and would unnecessarily limit color choices in an already limited palette.

Hi James,

I don’t think that was discussed directly, but in order for that to be an issue the controls in different states would have to be adjacent, i.e. touching. Even without a mention of states, I think that would be an issue in current WCAG conformance.

There was some discussion about whether ‘existing’ was a state, and people thought that wasn’t clear so ‘boundaries’ was added:
“Visual information used to indicate states and boundaries of active user interface components”

(Still with the intent that if it isn’t there, you don’t have to add something.)

Does that help?


Regards, James

James Nurthen | Principal Engineer, Accessibility
Phone: +1 650 506 6781<tel:+1%20650%20506%206781> | Mobile: +1 415 987 1918<tel:+1%20415%20987%201918> | Video: james.nurthen@oracle.com<sip:james.nurthen@oracle.com>
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Received on Thursday, 16 November 2017 18:40:13 UTC

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