As @dalto said, the newer gnome apps are not very themeable. And Linux Mint might be using the older pre-libadwaita versions of these apps. But at least some of them can be made to use dark theme by entering the following from the terminal:
gsettings set org.gnome.desktop.interface color-scheme 'prefer-dark'
If you want to revert the setting back to the default value:
gsettings set org.gnome.desktop.interface color-scheme 'default'