GTK Files Sidebar

How are you getting Files to have the sidebar (left) dark but the rest light theme? Just like in this screenshot:
https://images.pling.com/img/00/00/36/00/71/1214931/preview-gnome-light.png

I've tried multiple themes Flat-Remix-GTK-Blue-Light-Solid, Flat-Remix-GTK-Blue-Dark but neither of these seem to do the trick...