WPT details: Web-platform tests for the parsing and serialization of ActiveText, Field, and FieldText have been added (https://github.com/web-platform-tests/wpt/pull/19856). System colors are platform dependent, so web-platform tests for the calculation of ActiveText, Field, and FieldText were not added.
Give users the ability to customize their sites with the relevant system colors when in forced colors mode. The keywords being added are ActiveText, Field, and FieldText. ActiveText is for active links. Field is for input field backgrounds. FieldText is for input field text.
ActiveText, Field, and FieldText have been added to the CSS Color Module Level 4 spec. ActiveText, Field, and FieldText will give users the ability to customize their sites with the relevant system colors when in forced colors mode.