RE: Windows high contrast mode.

Putting aside whether it fails WCAG for a moment, there are simple steps
that can be taken to alleviate some of the problems people using WHCM
encounter.

 

For example:

*	Not using CSS background-color  or background-image (e.g., for radio
button selection indication)
*	Not using colour as the only mechanism to convey information 
*	Using secondary focus indication mechanisms that show in WHCM
*	using the border property on buttons and fields even if set to
transparent

 

These are easy to achieve if not using a point and click black box platform.

 

 

 

From: BrianD <lists@briandalton.org> 
Sent: Thursday, April 23, 2026 7:00 PM
To: w3c-wai-ig@w3.org; w3c-wai-ig@w3.org
Subject: Windows high contrast mode.

 

Hi to all.

 

I've been asked to research if windows high contrast mode, that is altered
in the windows settings, touches off a specific WCAG success criterion? If
something fails under windows high contrast mode conditions, is it a bug or
a best practise?

Any research I've seen, states that if something fails when this feature is
activated, it can fail against many different SC such as: 1.4.1, 1.4.3,
1.4.11, and 1.4.7.

 

Have you found that to be the case? Or have you come across any resources
that say a specific success criterion covers it.

 

Any blogs, links or articles you've come across would be helpful here.

 

Thanks in advance.

Best wishes,

 

Brian Dalton.