Love it! Just started using Directory Opus and found the default theme okay but wanted a few changes. Yours is simple and clean, like Windows 10's design. I don't like the dark grey location bar (in mine since I'm using the default location and it isn't turning white like yours) but it should be easy to change.
By the way, how did you add those arrow buttons (the green ones, top left).
And, I wonder how you managed to remove that separator between profile tree and the lister view.