No color data saved by vtkVRMLExporter?

I was using vtkVRMLExporter to save a vtk scene to a VRML file (.wrl). The scene contains objects (tubes) that uses a vtklookuptable for the color assignment. But when I load the wrl file into paraview, it does not show proper colors. Just a default solid color. I’m using VTK 7.x. Is this a known issue or is there anything specific I need to do to make sure vtkVRMLExporter export colors correctly?

Thanks!
RP