Default overlay styles
Each overlay has a default Pen, Brush, Symbol (shape) and Font. These are set on the Styles tab of the Overlays dialog.
When an overlay is created (either using an internal dataset, a BDS file or an FDB file) it is automatically assigned a Pen and Brush which are different from those assigned to other overlays.
This is simply to differentiate the individual overlays; pens and brushes can be changed at any time. Likewise the default symbol called (dot) and the default font (Arial) can also be changed.
Set a scale for the overlay (select Overlays > Styles > Scale Override checkbox and enter the required scale).
Note: See also What is Scale?