I created this theme to match the Arc Dark theme I'm currently using in Jetbrain's IntelliJ IDE. Sharing for your pleasure!
The Active Title Bar colour can be changed in Windows Settings/Personalisation/Colours. Change this to #363D49.
To change the inactive title bar colour, you can do this easily with Winaero Tweaker, under Appearance/Inactive Title Bar Colour. Change this to 47, 52, 63 (R, G, B).
If anyone knows how to get rid of the white dotted outline on the file selection, please let me know.
There must be a way, as if I select 'Use Visual Style' (which, incidentally, overrides my highlight colours) the dotted outline is more subdued blue colour. Not sure if this is a Windows thing or Directory Opus thing, so I welcome any pointers!
Turn on Preferences / Display / Options / Use visual styles to draw items and then turn off Visual styles override file selection colors below it and it should look OK.
Any idea how to change the Quick Access visuals? It has a different folder view and I couldn't find the right option to change that or customise colours for it.