In vim, I can run set bg=dark and then vim will adjust all syntax highlighting to work on a terminal with a dark background (whether or not the background actually is dark, vim will assume that it is).
How do I tell emacs to assume that the background is either dark or light?
I've used the invert-face function in the past:
(invert-face 'default)
Or:
M-x invert-face <RET> default
I think the best approach to use is to use ColorTheme. Other options to customize the frame colors you can find here. I can't think about a single command, however you can start emacs with --reverse-video.
M-x set-variable <RET> frame-background-mode <RET> dark
see also the bottom of https://www.gnu.org/software/emacs/manual/html_node/elisp/Defining-Faces.html
Write this at the end of your ~/.emacs file :
;; dark mode
(when (display-graphic-p)
(invert-face 'default)
)
(set-variable 'frame-background-mode 'dark)
Note: The "when" sentence is there to avoid to invert colors in no-window mode (I presume your terminal has already a black background).
