https://bugs.torproject.org/31170#comment:8
I chose these icons for the "on" and "off" icons:
toolbar_icon_purple.svg → toolbar-on.svg
toolbar_icon_grey.svg → toolbar-off.svg
I then made toolbar-running.svg by copying toolbar-off.svg and changing
the stroke and fill from #4A4A4F to #40E0D0.
In Firefox, this requires version 67 for support for
prefers-color-scheme media queries.
https://hacks.mozilla.org/2019/05/firefox-67-dark-mode-css-webrender/
To force Firefox into dark mode, set ui.systemUsesDarkTheme=1 (and
optionally browser.in-content.dark-mode=true, to put pages such as
about:addons into dark mode as well) in about:config. You can check if
it's working at https://bugzilla.mozilla.org/, which has its own
dark-mode styling. Note that this kind of dark mode is *independent* of
the "Dark" theme that can be selected in about:addons.
Chrome requires version 76 for prefers-color-scheme. You can force it by
running with the --force-dark-mode command-line option.
This one was missing from the redesigned icons. I made it by making a
copy of status-on.svg and changing the fill from #8000D7 to #40E0D0.
I didn't make a separate dark-mode version of the icon.
The semicolons made it look like the end of a declaration. I got these
errors in the Firefox console:
Expected declaration but found ‘1px’. Skipped to next declaration. 1 embed.html:29:17
Expected declaration but found ‘-1px’. Skipped to next declaration. 1 embed.html:30:17
I'm intuiting that the purpose of linking to github was to show the
README, not to link to the source code per se, so I changed the link to
point to the wiki page rather than gitweb.torproject.org/....
https://bugs.torproject.org/23947#comment:15
This is a hedge against any bugs that may cause the badge to hang when
left running for a long time, and it also means that badges will
effectively check for updated code once a day.