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