vtkBlockColors vs Block id

Hi Paraview community,

I am wondering what is the difference between the numbering in vtkBlock and Block from the properties panel. For instance, in the screenshot attached, why are the numberings from `vtkBlockColors’ and ‘Blocks id’ different?

Many thanks!

One is automatically generated on the fly (vtkBlockColors), one is coming from the data (Blocks Ids). They may or may not contain the same information.

Thank you so much for the explanation!