how do I change the color of the edges in the "Wireframe with hidden edges" view to the color black? When I change the color of the object to black under View -> Edit Object Display I get grey edges instead of black ones.
I want to have black edges because they are more visible on screenshots when the background is white.
"Wireframe with dim edges" will automatically dim the hidden edges to a gray color. If you want all the edges to be black (the body color), pick "static wireframe".
Still seems gray to me but maybe the lines are just too thin? But changing the line width under Visualization Preferences doesn't seem to change anything at all. Any other hints on how to make edges more visible when I export them to jpeg/png?
EDIT: added a zoomed in view of one of the edges.
For the Wireframe with Hidden Edges mode, edges are hardcoded to be based on body color, you'll notice the option in Visualization preferences to change the edge color is disabled for this rendering mode.
Why not just use Shaded with edges?
Yes, I have noticed that the colors are based on the body color. That is why I am wondering why the edge color is rather gray than black although the body's color is black.
Using shaded with edges is an option, yes. But sometimes I just find wireview less busy and, thus, better to look at.
In that case, they should be black but since they are pretty thin by default might appear grayish depending on your display.
Turning body color to black probably makes shaded rendering modes pretty difficult to deal with.
One compromise you might try: you could just setup a hidden line display in drafting and capture that.