Revit :: Import And Override Material Settings

We work with prototype buildings that can have material color variations from site to site.  For example, a brick version of a prototype can have several different brick palettes from which to choose.
 
I'm thinking fo creating generically-named materials in the prototype set - Brick-Base and Brick-Accent, for example - with the idea that the specific material data for the function can be changed for each site-specific building.
 
While this certainly can be done manually, is there a way to import material data - and not just rendering appearance data but all of the data - into a model, either from another model or better yet, from some sort of data file?  Ideally you would only import the materials for which you need to change the data.