Hi Michael,

> Btw. is it possible to seperate optical (f.e. by color)
> "seams-curves" - "intersecting curves" and "construction-splines"?

You can control the colors of things by assigning them different styles - that's done by the properties panel or by clicking on a color swatch in the scene browser:
http://moi3d.com/2.0/docs/moi_command_reference11.htm#propertiespanel
http://moi3d.com/2.0/docs/moi_command_reference11.htm#scenebrowser

Basically colors are left to be used as a kind of grouping mechanism by your own preference, so there isn't anything like make all construction splines a particular color separate from the style system.

- Michael