Labels not appearing flush on the face on vtkhexahedron

Hi VTK experts,

I’m displaying a bunch of vtkHexahedrons in an vtkUnstructuredGrid and trying to display custom labels on each face/side of each hexahedron. I’m currently using one actor for the vtkUnstructuredGrid and one actor for vtkLabelDataMapper and adding these to a vtkPropAssembly to display them. The labels are appearing though they are not flush on the face of the vtkhexahedron. How can I achieve this ? Is this the correct approach to take ? Also how can I use different colors to display the different labels on each face of the hexahedron ?

I’m new to VTK so any pointers/suggestions are greatly appreciated.

Thanks in advance,