Accessibility level AAA: Accordion toggle icons not displayed in inverted colour mode

[tjsilver]

When users view the accordion in an inverted colour scheme, the toggle icon is not displayed. As a result of this users might not be aware that these are expandable elements.

The suggested solution involved using a media feature called -ms-high-contrast that is a) non-standard and not for use in production. There is a newer feature called forced colours that could perhaps be used instead, but this is not widely supported by browsers as it's in active development.

The suggested solution included also adding a hover state to the accordion element, to act as an alternative method for indicating that the element can be interacted with.

Screenshots

Inverted colour mode

Default mode (for reference)