I made it work in some way. There was a bug in line,
ids2.InsertNextValue(i)
It should be,
ids2.InsertNextValue(self.vtk_list.GetId(i)).
Looks like it was visualizing but colors were not helpful.
It is still not perfect as I am not able to change the colors of points according to selection or cluster but this is a small problem which I am planning to solve later.
