I have set up a material to a part in a subassembly, which is patterned in an higher level assembly. And it fails to update the appearance in this particular component part as shown. I also tried removing all the materials, still the material didn't remove from that particular component part. I tried also changing the display state, but it also reverts back to the "all display state" option once I click okay.
Note. This component part is patterned and all other identical components updates to the black colour. Except this particular one.