In Sectioning Settings, you can control the visibility and appearance of contours generated by section planes cutting through components (see The Sectioning Tool). While you're modifying the Sectioning Settings, the 3D view is visible and changes are dynamically updated in the model.
To access the settings, click File, then Settings, then Sectioning.
Show sectioning lines: When checked, sectioning lines are shown. If unchecked, the Line Color and Line Thickness options are disabled.
Line color: Set sectioning line color. To change the color, click the color box. A dialog opens. Select the color and click OK:
Line thickness: Set sectioning line thickness. For close up views of detailed components, a lower value is recommended.