You can change the default style and name format settings for sample lines. Settings are handled in a standard way throughout Autodesk Civil 3D via the Settings tree at three levels: drawing, feature, and command.
To change settings for a specific command, use the Commands collection in the Sample Line collection.
The default styles and name format settings for sample line commands are described in this topic. Drawing ambient settings are described in Ambient Settings Tab (Drawing Settings Dialog Box).
In the Edit Feature Setting - Sample Line dialog box, note that appears next to the settings for default styles and default name format, marking them as specific to sample lines.