Okay, so I'm a bit of a macOS boomer. Having used macOS since long before Mojave's dark mode, I'm accustomed to the regular light appearance of the windows - but I always enabled the "Dark menu bar and dock" option as I loved the look. While I still like dark mode (and use it on iOS), the hybrid light/dark mode on macOS is still my favourite!
The following commands restore that functionality:
Window Server
defaults write -g NSRequiresAquaSystemAppearance -bool Yes
Notification Centre
defaults write com.apple.notificationcenterui NSRequiresAquaSystemAppearance -bool No
Control Centre
defaults write com.apple.controlcenterui NSRequiresAquaSystemAppearance -bool No
About This Mac + System Profiler
defaults write com.apple.SystemProfiler.AboutExtension NSRequiresAquaSystemAppearance -bool No
defaults write com.apple.SystemProfiler.AboutExtension NSRequiresAquaSystemAppearance -bool No
Restore the default full dark mode functionality.
Window Server
defaults write -g NSRequiresAquaSystemAppearance -bool No
Notification Centre
defaults write com.apple.notificationcenterui NSRequiresAquaSystemAppearance -bool Yes
Control Centre
defaults write com.apple.controlcenterui NSRequiresAquaSystemAppearance -bool Yes
About This Mac + System Profiler
defaults write com.apple.SystemProfiler.AboutExtension NSRequiresAquaSystemAppearance -bool Yes
defaults write com.apple.SystemProfiler.AboutExtension NSRequiresAquaSystemAppearance -bool Yes