Pseudo-element colours are no longer overridden by Windows High Contrast in Chrome/Edge 124

[querkmachine]

Description of the issue

Versions of Google Chrome and Microsoft Edge from 124 onwards do not apply the expected override colours to pseudo-elements in Windows High Contrast Mode.

Significant issues:

• Lists — bullet points and number markers are always black instead of matching the text colour
• Checkboxes — checkbox border is always rendered as black instead of matching the text colour; the check image is also always rendered in black
• Radios — radio button border is always rendered as black instead of matching the text colour; the radio's checked state is also always rendered in black

Less significant issues:

• Accordion — toggle arrows are always black instead of matching the link colour
• Details — toggle arrow is always blue instead of matching the link colour
• Back link — back arrow is always blue instead of matching the link colour
• Breadcrumbs - separator arrows are always black instead of matching the text colour
• Header — the mobile menu toggle's arrow is always rendered as black instead of matching the text colour

Screenshots

Expected result in Edge 123 on Windows 10 (via AssistivLabs)

Unexpected result in Edge 124 on Windows 10 (via AssistivLabs)

Steps to reproduce the issue

Activate Windows High Contrast Mode on a Windows 10 or Windows 11 PC. View the design system examples or review app examples using Google Chrome 124 or Edge 124 or newer.

Actual vs expected behaviour

Elements should be rendered in a colour appropriate to the High Contrast Mode being used, rather than being static.

Environment

Reproduced in:

• Operating system: Windows 10, Windows 11
• Browser: Chrome 124, Edge 124
• GOV.UK Frontend Version: 5.3.1

I also tested in Edge 123 on Windows 10 and Firefox 125 on Windows 11, neither of which exhibited this issue.

[querkmachine]

A fix for this appears to have shipped in bugfix releases for both Chrome 124 and Edge 124 in the last week and a bit. It is also in the version 125 releases of each browser.

If the issue persists, first ensure that you're using one of the below versions or newer. Update your browser if it is older.

• Chrome 124.0.6367.208
• Edge 124.0.2478.105