The command SCATCHMENTSTYLES creates and edits the styles of Catchments.
To use, call SCATCHMENTSTYLES from the command line, menu, toolbar, in the Ribbon choose the style you want to edit:
On this screen you can:
Catchment style allows you to configure the appearance of catchment catchments, showing their polygon, thalweg, hatch, etc:
See the topic Toolspace / Settings / Catchment Styles to learn more