
About the titlebars, then two possibilities.
It's default windows titlebar used whenever app doesn't itself change that bar, and I read you can change that(I cannot test it as my windows VM unactivated, so such settings blocked), by using a dark accent color and then choosing to show the accent color on title bars, in windows settings under 'Settings > Personalization > Colors' > Under 'Show accent color on the following surfaces', put a check on Title bars and window borders.
Then last possibility is that the built-in adwaita-dark theme actually itself defines the titlebar to be black, but however the max ,min and close buttons doesn't look 100% "windows-like" in this mode, but pretty close regardless. Also there has been reported one or two bugs with having the app mess with the titlebar, so it was decided to disable it and use windows default titlebars. You can circumvent this, and get the black titlebars back on adwaita dark theme, but mind you this then works for all gtk apps, and also as said there's one or two bugs you could experience, I believe one is you need click maximize twice whenever going from minimized to maximized from the tray-icon or something, if using such. but anyway, easiest way to get this changed is to open cmd-prompt with 'win+r > cmd' and run 'setx GTK_CSD 1'. If changing mind then can revert back to default again through opening said cmd-prompt and running 'reg delete hkcu\environment /f /v GTK_CSD' and reboot for changes to take effect.
Let me know if need clarification on any of this.