If you need to quickly overlay one drawing over another but not have a confusing mess
a quick handy way I have found is using the Selection option in Styles to
change the default [usually blue] colour into something more useful in your presentation.
In the image below you can see I have changed the Selection colour to dark green so
I can subtly separate the original CAD linework from the new design of pathways...
Of course this only works for screen captures [raster] files
Hope this helps someone!