I just upgraded to Ubuntu 19.10, from 19.04.
I use the default dark Adwaita theme, but the calendar and WiFi Control Center are showing as white. I also tried the dark version of the Yaru theme, with the same result.
How do I troubleshoot this issue?
so if you run
sudo apt install gnome-shell-extensions
you will download an extension called "user themes". Then in gnome tweaks you can go to appearance and change the "shell" to united-ubuntu-dark and that will change the top bar to the normal yaru dark colors.
Only downside is the app drawer icon is the Ubuntu logo instead of the 9 dots.