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RE: High Contrast support with Browsers.

From: Jonathan Avila <jon.avila@levelaccess.com>
Date: Wed, 30 May 2018 13:13:50 +0000
To: Ian Sharpe <themanxsharpy@gmail.com>, WAI Interest Group <w3c-wai-ig@w3.org>
Message-ID: <BL2PR03MB387F46849978A10FDAF6A85F16C0@BL2PR03MB387.namprd03.prod.outlook.com>
On Windows there is a flag for high contrast (SPI_GETHIGHCONTRAST)


Jonathan Avila
Chief Accessibility Officer
Level Access
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From: Ian Sharpe <themanxsharpy@gmail.com>
Sent: Thursday, May 10, 2018 6:35 AM
To: Jonathan Avila <jon.avila@levelaccess.com>; WAI Interest Group <w3c-wai-ig@w3.org>
Subject: RE: High Contrast support with Browsers.

From an accessibility perspective, I feel all apps, including the browser, should respect native OS settings / colour scheme etc. However, I’m not sure it makes sense for apps to respect the native OS theme in all cases, as many people may use a different colour scheme for any number of reasons,  including personal preference. I think these users would actually be more surprised / confused if they went to a site of a well-known brand and the site was displayed using their native OS theme instead of the usual branding for example? I’m not sure marketing types who spend a lot of money on website branding / colour schemes would be particularly happy either?

That said, for me at least on Windows 10 using the inverted high-contrast theme, both Firefox and Edge respect the native colour scheme, but Chrome doesn’t, so it would seem there is some ambiguity around this issue?

I guess the obvious next question then is how is the browser expected to *know* when a user is using a high-contrast or custom theme for accessibility reasons across all possible platforms?

May be FF and Edge are making assumptions on the basis that I am using a high-contrast theme (set via ease of access settings), or because I’m using a screen reader or have other accessibility settings enabled, which for my particular use case is great as I didn’t have to do anything to get my desired behaviour, and I would prefer it if Chrome adopted the same approach as well. But I’m not sure how feasible this approach might be for all platforms? Indeed, what about the case when a user creates a custom theme for accessibility reasons but makes no other accomodations?

Based on the above, here’s my proposed logic:

If an app can determine whether the OS has been customized for accessibility reasons, the app (including browsers) should respect these settings by default, so that the user is not required to do anything themselves.

If the app isn’t able to make this assumption, the app should do nothing by default, but should provide a switch to enable the user to change the behaviour of the app to respect native OS settings if required.


From: Jonathan Avila<mailto:jon.avila@levelaccess.com>
Sent: 09 May 2018 12:33
To: WAI Interest Group<mailto:w3c-wai-ig@w3.org>
Subject: Re: High Contrast support with Browsers.

I would consider the need for high contrast applicable.   We do have some techniques to support it such as Failure F3 relates to background images when css images are not displayed.

Sent from my iPhone

On May 8, 2018, at 10:23 PM, Sean Murphy (seanmmur) <seanmmur@cisco.com<mailto:seanmmur@cisco.com>> wrote:

General query in relation to high contrast with browsers. Should the browser honor the OS high contrast settings or should the CSS override the OS high contrast? My view is the browser should honor the OS high contrast settings. Not sure if this is the case now.

Sean Murphy
Accessibility Software ENGINEER
Tel: +61 2 8446 7751

Cisco Systems, Inc.
The Forum 201 Pacific Highway


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Received on Wednesday, 30 May 2018 13:14:20 UTC

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