Where does the data come from? Can they save the surface in PLY format when they acquire it?
Adding vertex color loading to VTK OBJ reader would be quite straightforward, probably less than one week for a developer who knows VTK. But you either need to wait until a funded project needs this feature, hire someone to do it or do it yourself.
You could also try converting the OBJ to PLY using meshio or similar Python packages, if converting using MeshLab is too complicated or takes too much time.