Operating system high contrast mode (Android, iOS) - Should we care about it?

[dannymartucci]

Hi,
I have a question on how to work with the proprietary high contrast modes that are defined by system for the main mobile OS.

In particular I'm working as an AX expert for a client which has a mobile application. This app relies on a complex design system that already provides component both for regular and dark mode - those component are compliant with the thresholds defined for level AA.

Today the user can switch between the two modes and both are correctly contrasted.

They asked me if they should be compliant with the high contrast mode defined by Apple and Google because this would actually lead to the creation of two more versions of the design system: in fact today turning on such modes doesn't change anything within their apps (since, again, they are already compliant).

I advised that what they currently have in place is fine and they should not worry about that because any OS has different rules (e.g. turning on HCM forces dark mode on Samsung but not on Pixel) and it would be crazy work to meet all of their requirements, also from the WCAG perspective.

I advised them that they should only be compliant with the WCAG AA guidelines and nothing more.

Am I correct or should we worry about the proprietary high contrast mode implemented within the operating systems?

Hope the issue is clear, thanks in advance!

[patrickhlauke]

WCAG strictly doesn't concern itself with high contrast modes / forced colours that are purely under the control of a browser/OS. it'd only be a WCAG concern if it's done by the author...for instance, if an author explicitly used something like media query features to define explicit colours to use when the user has set prefers-contrast: more

[patrickhlauke]

of course, WCAG is only the floor, not the ceiling. doing the absolute minimum may not be a good approach here. and trying to go beyond WCAG may yield more accessible results

[dannymartucci]

Thanks for your reply! Of course WCAG is only the floor but in this case the question was "is this mandatory?" because it's related to budget stuff and they wanted to understand if they were forced to do it.

I think you confirmed that is not something mandatory.