I've used gnome-shell now for daily for a couple of weeks and is still find it very difficult to easily see which windows is activated. When I for instance have two terminal windows or two nautilus windows open on a Workspace it is very unclear which of the two has focus.

The only difference between a window with focus and a window without is the font of title of the window.

I would much appreciate an improved visual aid to clearly see which window is active / has focus to increase productivity.

The current situation is especially slowing down work when you are out of flow (either by switching workspaces or because you went for a cup of coffee) and want to quickly start working again / get back into flow. You (I) always have to take a look at which windows actually has focus.