The collection of all link style objects are found in the CivilDocument.Styles.LinkStyles property. This style object contains properties for adjusting the visual display of assembly and subassembly links.
Note:
Link style objects are not used directly with link objects, but are instead used with roadway style sets.
// Add a new link style to the document:
objId = doc.Styles.LinkStyles.Add("Style2");
LinkStyle oLinkStyle = ts.GetObject(objId, OpenMode.ForWrite) as LinkStyle;
oLinkStyle.LinkDisplayStylePlan.Color = Color.FromColorIndex(ColorMethod.ByAci, 80);
oLinkStyle.LinkDisplayStylePlan.Visible = true;
ts.Commit();