* dark grey background (system default)
* pure white foreground (system default)

* when 'ui.use_native_colors' is true, some elements in the webpage turns out to be "white over grey"
* when 'ui.use_native_colors' is false, while the background colour turned into white, the foreground colour did not return to black.

* install Arc X Theme for Windows 10 (follow the instructions)
* open a virtually arbitrary page that contains a text input box
* bug found

My Firefox is a 73.x stable version, running on a slightly modified x86_64 Windows 10 1903 with: * dark grey background (system default) * pure white foreground (system default) In Google Chrome all elements follow the "black over white" rule regardless of system default color pref. While Firefox does not. In the figure below these phenomenons exist: * when 'ui.use_native_colors' is true, some elements in the webpage turns out to be "white over grey" * when 'ui.use_native_colors' is false, while the background colour turned into white, the foreground colour did not return to black. This leads to my suspicion of 'ui.use_native_colors' does not at all control the foreground colour. And probably no key does. - - - - - - - - - - - - Reproduce the bug: * install Arc X Theme for Windows 10 (follow the instructions) * open a virtually arbitrary page that contains a text input box * bug found