Import Velocity Streamlines

Hi everyone!
I am working on a method to export my CFD results from Simcenter STAR-CCM+ into ParaView.
I imported a *.cgns file from STAR-CCM+ with the velocity field function.
I was able to create slices to show the velocities and that worked greatly.
I also imported streamlines as *.vtk and applied the velocity field function.
My problem is: I also have to visualize Iso Volumes of Low Velocity areas.
I can export them STAR-CCM+ as *.vtk and import in ParaView, but they show no velocities quantitatively, theyre just white (Solid). Is it even possible to import Iso Volumes into ParaView with applying the velocities there?

Thank you very much for your help!