Show edges with another color

Hello,

i am very new to Helix.

it works fine to simple load an *.stl file.

i want to change the color of edges, to better see the triangles .

how i can do this?

Here is the starting code, I think i have to do something here but I do not know what to highlight the edges with another color, black for examble.

what I have to do? i am not able to find a solution in the forum, but i think it is not about the forum it is about that i am very new to helix and do not know what to do...

regards, mapa

System.Windows.Media.Media3D.Model3D newModel3D;
System.Windows.Media.Media3D.Material mat = new System.Windows.Media.Media3D.DiffuseMaterial(System.Windows.Media.Brushes.LightGray);
newModelImporter.DefaultMaterial = mat;
newModel3D = newModelImporter.Load(GetStlFile());

viewer3D = new System.Windows.Media.Media3D.ModelVisual3D();
viewer3D.Content = newModel3D;
............