Assign material to entity existing in a component instance (imported dwg)

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The “debug functioning” you are using here - writing a puts inside the code to some “critical” place - is totally fine. I’m using that too and never ever used VScode or any other debugger… :innocent:

Back to topic:

It is modified code!
Also I do not see how did you called (witch parameters you used for) the def color_my_componet method.

I guess you used “Test_Project - 3D View - {3D}.dwg” as a first parameter.
Therefore, certainly there are no faces, because that definition does contains only a instance of the “Family_Test - Family_Test-67707-3D” definition. The faces are in the second (nested) one.