Currently the applet displays "Night Color is active (%screen color
temperature% K)" all the time even if the screen is not actually
red-ish. It may be really confusing for ordinary people and I expect
that a few bug reports saying "the applet shows that Night Color is
active, but in reality it isn't" might be reported.
The best thing would be to display "Night Color is not active, the next
transition will start at %datetime% and end at %datetime%" or something
along the line.
This patch is still WIP because I'm not 100% sure how to present this
kind of information to user.