On the default Ubuntu Gnome light theme there is white border around window, and shade effect - it is easy to spot how large window is and where are its edges.
On the dark theme multiple overlapping windows are visually mixed together and it is very hard to spot where is the edge of each window. Possibly there is a shade but on the dark theme it is not seen even if exists.
is it possible somehow to specify the color of the window border? For example to put some lighter color like whitish or some other light color to be in contrast to dark windows.