Adds a new contour to the Contour list box.
Hidden: Hides a contour type (Hidden Objects)
Contour Name: Each contour type is assigned a default name.
When a contour type is marked as hidden, it is not available from the Contour drop-down list in the Main toolbar. If you are using a contour type, then mark it as hidden, the traced portion becomes invisible.
All Visible: All hidden contours become visible.
None Visible: All contours are hidden.
Set Color Button: Highlight a contour type then click the button to change the contour color (you may also double-click the color box next to the contour name).
Default Colors: Restores the default colors.
Also see Tracing contours