if i may add my grain of sand to the conversation, something ‘missing’ in paraview is to be able to do something similar to this (give a color for each region/block) but for specific fields. something like the behavior of what salome calls ‘auto color’. that it would check the number of different values of a int field and then color them with a different color each. what it is actually doing vtkBlockColor but for any integer field. I mentionned about this here. if extended this way it could be used also for the coloring of the blocks… I am thinking cases such as connectivity output and being able to color each region by a different color ‘interpret them as the blockID’