Hi Michal -
RH-65387 is still open and currently on the “Future” list.
Did you try the BlackWhiteSwitcher plug-in that Steve wrote?
-wim
Hi Wim,
Yes, I did. It is working, but only partially. It correctly sets the object’s colour (in this example from black to white). But it is not affecting linework while drafting. On the black background, the colour of the drafted polyline is not converted (it is black) until the process is finished. Only then it turns white. So I can’t properly see what I am drafting until it’s too late 
.
Also, not ortogonal lines (white on black) seem to be “dashed” or “dotted” on my side.
Edit1:
A wonderful addition, but it needs updating and development،To work better, with dark mode.
My guess is that the lines you are seeing while drawing a polyline are not added to the document yet but a temporary Display Conduit to “preview” the lines before committing the result/command at which point the lines DO get added to the document and picked up as “curves” in the Display Mode and colored white/black accordingly.
So the “dynamic preview” of the polyline drawing has curve color attributes that aren’t being set by the BlackWhiteSwitcher logic and taking the default color of “Black” regardless.
Not that that helps you with a solution but I think that’s what is happening here…