How to apply material for parent group while children are having different materials (redshift)


I created a lego-man and I gathered all body parts ( head, hands, legs, body etc…) under one parent.
I set a uv and a graphic I created on photoshop.
I would like to set imperfections on the parent (the whole charchter) and of course leaving the materials set for every part.

When i’m setting a material for the parent, i effects the whole lego-man, overwriting the materials under the partent on the children.

will be more than happy for advice :slightly_smiling_face:
thank you!