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Re: rely on a browser's high contrast mode

for

From: Jonathan Avila
Date: Jul 31, 2019 2:56PM

In my experience the Chrome high contrast mode extension applies a filter to the page and while it makes some text higher contrast it can also make other text lower contrast. I find it unlikely for all of the pages that it wouldn't break something else bringing some other text lower than the threshold. Browser extensions also are not available on mobile browsers. While mobile platforms have some accessibility settings to invert colors or increase contrast again I don't think you could safely rely on these assistive technologies for a public site -- although strictly speaking only one combination is needed to claim conformance. From a functionality standpoint -- an argument under the ADA could be made that if content functionally works with assistive technology even if not conforming to WCAG that it can be used. For example, a screen reader that guesses form labels for form fields could be relied upon instead of marking up your form fields with explicit labels. This is risky.

In addition, the contrast requirements under WCAG are minimums. They are not high contrast values and are not meant to address needs of people who need high contrast -- they are meant to provide a minimum level of contrast for users. Forcing a user who only needs a minimum to use a high contrast mode does not make sense. A better option if the page colors absolutely can't be changed is to add a switch that provides an increased contrast option to meat the minimum. This option would be available to all users including those with platforms and browsers without contrast options. The argument that changing a gray line to be slightly darker will cause an organizations customers to leave is often used but is likely just someone defending their style decisions rather than based on actual data. Brand colors are important but most customers will find that you can get appealing brand colors with sufficient palette options that have sufficient contrast or that small modifications can be m
ade with a switch control allowing user preference before rebranding is done with inclusive design taken into account.

Jonathan


From: WebAIM-Forum < <EMAIL REMOVED> > On Behalf Of Birkir R. Gunnarsson
Sent: Wednesday, July 31, 2019 4:10 PM
To: WebAIM Discussion List < <EMAIL REMOVED> >
Subject: Re: [WebAIM] rely on a browser's high contrast mode

CAUTION: This email originated from outside of the organization. Do not click links or open attachments unless you recognize the sender and know the content is safe.


For the purpose of achieving absolutely minimal conformance to WCAG
2.0 this is an interesting question.

I invite you to peruse the wonderfully complex document that is the WCAG 2.0 conformance requirements https://www.w3.org/TR/UNDERSTANDING-WCAG20/conformance.html
particularly the "conforming alternate version" and "accessibility supported" sections.

Note 7 under "understanding conforming alternate versions" says:
"Setting user preferences within the content to produce a conforming version is an acceptable mechanism for reaching another version as long as the method used to set the preferences is accessibility supported."

As long as you can open your browser menu and turn on high contrast mode (which you can with most assistive technology browser combinations I aware of) this sounds like making certain features accessible in high contrast mode would pass the minimalist definition, much to my disappointment.

Forpractical reasons you wouldn't want to rely on this:

As already mentioned, high contrast mode differs between browsers and operating systems and while it can fix one area of the page it could render other parts amost totally impossible to read (and for the page to pass WCAG the entire page ust be accessible in the chosen mode, not a page that requires you to switch between multiple modes to achieve full conformance). In other words, and in my understanding, the page must fully pass color contrast requirements in high contrast mode, notjust the sections of it that fail in normal mode.

Even if high contrast mode is available, would users know about it (would you be able to tell your grandma to just turn it on), similar arguments can be made for text resizing etc. but it is still a valid usability argument.

That designer should just make the page color scheme accessible, it will save major headaches, complications and sleepless nights in the long-run. ;)



On 7/31/19, Farough, David (CFP/PSC) < <EMAIL REMOVED> > wrote:
> Check out the following article from Scott O'Hara on other high
> contrast issues.
> https://www.scottohara.me/blog/2019/02/12/high-contrast-aria-and-image
> s.html
>
> > > archives at http://webaim.org/discussion/archives
> >


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