sounds like it turns your computer into a tor exit node?
Not at all. Snowflake belongs to the family of pluggable transports, and offers a connection to an entry node in the Tor Network. Just like a traditional bridge, with the advantage that the higher number of individual, constantly moving IP's makes blocking them by oppressive regimes more difficult.
It uses WebRTC to disguise the traffic as a real time peer to peer communication, like video/voice call.
Defining sidebar_bg_color does not work?
see libadwaita named colors
GTK Inspector comes with GTK, you don't need to install it.
Enable it with gsettings
gsettings get org.gtk.Settings.Debug enable-inspector-keybinding true
so you can invoke it either by running
GTK_DEBUG=interactive application-name-here
or, when alredy using the application, via Control + Shift + I/Control + Shift + D