With the latest Google Chrome updates, if you use macOS dark theme, Google Chrome will switch in dark mode as well by default.
Usually I love dark themes for everything, but I’m not a fan of of the dark theme for Chrome provided by Google — I dunno why, maybe a matter of time to get used to it.
Anyway, I you want to revert back to the classic Chrome theme you can run the following command to do so:
defaults write com.google.Chrome NSRequiresAquaSystemAppearance -bool yes
Then, restart Google Chrome.
If you want to re-enable dark mode later just run:
defaults delete com.google.Chrome NSRequiresAquaSystemAppearance