# vtkBlockColors vs Block id

**URL:** https://discourse.paraview.org/t/vtkblockcolors-vs-block-id/16326
**Category:** ParaView Support
**Tags:** vtk
**Created:** [March 13, 2025, 7:11pm UTC](https://discourse.paraview.org/t/vtkblockcolors-vs-block-id/16326 "2025-03-13T19:11:00Z")
**Posts on this page:** 3
**Page:** 1

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### Author: ![Hemiao\_Zhang](https://discourse.paraview.org/letter_avatar_proxy/v4/letter/h/858c86/32.png) [@Hemiao\_Zhang](https://discourse.paraview.org/u/Hemiao_Zhang)
#### Post date: [March 13, 2025, 7:11pm UTC](https://discourse.paraview.org/t/vtkblockcolors-vs-block-id/16326/1 "2025-03-13T19:11:00Z")

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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!

 ![blockID](https://discourse.paraview.org/uploads/default/original/3X/7/1/71ff3c41543eed9b4ef92be40d66adc4d27ff6d1.png)

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### Author: ![mwestphal](https://discourse.paraview.org/user_avatar/discourse.paraview.org/mwestphal/32/17_2.png) [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [March 14, 2025, 8:35am UTC](https://discourse.paraview.org/t/vtkblockcolors-vs-block-id/16326/2 "2025-03-14T08:35:28Z")

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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.

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### Author: ![Hemiao\_Zhang](https://discourse.paraview.org/letter_avatar_proxy/v4/letter/h/858c86/32.png) [@Hemiao\_Zhang](https://discourse.paraview.org/u/Hemiao_Zhang)
#### Post date: [March 14, 2025, 6:13pm UTC](https://discourse.paraview.org/t/vtkblockcolors-vs-block-id/16326/3 "2025-03-14T18:13:12Z")

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Thank you so much for the explanation!