Changing individual part colours in an assembly

Hi,

Ive created an assembly of parts that have had a powdercoat finished applied to the top level assembly. All the parts in the assembly are steel except a plastic washer on top.

What is the best way to bring across the washer parts original colour? Whatever I do seems to do nothing or destroy the top level colour.

I can get around it by individually changing the single part colours but this isnt a great use of time.

Another issue is when I RMB on the part in the assembly, the menu appears and I click on the appearances button which creates the popup appearances menu (all good so far) but when I move the the popup menu, it vanishes. Any suggestion? Currently using 2012 SP3.

Thanks, Fraser

SolidworksAssemblies