Chrome OS may be about to usher in dark mode, but so far, it has only been found in the empirical Canary channel. This version can only be accessed from the chrome book that has been switched to special developer mode (not to be confused with Chrome OS developer channel). Canary operation can be very unstable, so it is not recommended to risk switching to this version for this function.
Now, to activate dark mode on the Chromebook, you need to first cut the operating system into the Canary channel, and then activate by opening the Chrome browser. Enter chrome：//flags/#enable-force-dark and chrome：//flags/#enable-webui-dark-mode in the URL bar to find the switch entry.
But so far, the system level Chrome OS dark mode has some bugs that apply to the entire user interface, not just as a dark background.
In the past few months, Google has launched dark mode versions for its Gmail, Google Calendar, Google fit and its mobile apps, and IOS and Android both started supporting dark mode at the system level last year.