There is an appearance that has been applied to the assembly level that I can not get rid of. I have tried removing the appearance and it just keeps coming back. It doesn't show up when rendering the assembly but when I try and insert that assembly into another assembly it overrides the lower level appearances and all I get is the assembly level appearance. Any help?

This is the apperance applied to the assembly that I can't remove.

It does not show up in the tree at the sub assembly level and does not affect the rendering.

But when I try and insert the assembly into another assembly it shows up and overtakes all the lower level appearances. The other sub assemblies do not have appearances applied at the assembly level. Again I have tried removing the appearance and it immediately comes back.

Thanks