[vtkusers] streamline visualization

[Wapur.com]

Hi,

I have streamlines to visualize. I do not want to use tube filters. So I 
just render lines in my polydataset.
My problem is that how can I add shadow so that they are distinguishable 
when I look to a large number of parallel streamlines which are in same 
color.
Also when I assign color to them they look very bright. (I assign color 
in RGB mode) How can I get less bright colors like matlab plots?
One more thing that just came to my mind is when I increase the line 
thickness the smoothness disappears. Is there a way to manage this?
Thanks.

Emin