From bug 1121373 comment 4:
> I've also noticed that the background color of the label for "today" when
> systemcolors are active is different than before the introduction of the css
> variables (now is Highlight, before it was absent).
> Looks like it needs a different variable for the background in the rule
> in order to have the possibility to differentiate the background in the
> systemcolors case.
Created attachment 8560993 [details] [diff] [review]
The foreground- and background colors are only inverted in systemcolors mode. Thus needs to double the variables to not mess in normal color mode.
Pushed to comm-central changeset 7b97c6188612