Creo import direct modling parts/assemblies from windchill - assemblies missing part colors

When I load a Direct Modeling part out of windchill anything ist ok regarding colors - same as in native direct modeling

When I load an assembly out of windchill the colors of the included parts are gone/lost - I see only standard grey parts. 

How can I bring creo to show the songle part colors of these imported assemblies?

Assembly nativ Direct Modeling

Same Assembly loaded via Windchill into Creo