Provide guidance and examples that promote using media queries to set colors when high contrast settings are enabled

[jongund]

There seems to be good support for the forced-colors media query.

I am using this approach in the proposed updated rating slider example.

I think we should update examples that are relying only on currentColor to provide a more modern and flexible way to support high contrast user preferences. The use of only currentColor is not very practical in most production settings where branding colors would limit the ability to rely on currentColor. The media query would allow us to specify system color values like canvas, canvastext and linktext.

More information on system colors.

I think we should update the other slider examples and review other APG example where the media query would be useful in other APG examples.

We need some guidance on supporting high contrast settings in general under the practices.