I have the dark theme enabled but half the toolbar is light gray, the main left part is dark (with a gradient). Also, colors are not universally dark. All the dialogues, window elements, and pull down menus are bright white with black text. Do you remember some of the Microsoft Home products from the late 1990s and early 2000s? They had a universal dark theme before anyone called it dark theme.... they perfectly mimic what I would expect in a dark theme. I'm using a hi-DPI display on a Microsoft Surface laptop.
Steps to Reproduce:
1. Options --> Personalization --> Preinstalled theme --> "Dark"
Only the toolbars are dark. Nothing else is.
User Profile Reset: No
I think it's a dupe of bug 118320
*** This bug has been marked as a duplicate of bug 118320 ***