Change or influence color/material of linked in group object, possible?


I want to setup a “master copy” which contains all frequently used objects as links (group chosen so as to be able to position it in the project). Some of these items we have in stock two variations, black and white (some of the panels). I have only made the black variation where I can update the materials if needed. When linked that possibility is removed, and I want to maintain the link. I have several of these objects in the “masterfile” at a specific layer, and will be inserted as required by the project by “insert group instance”. Is there any way I can override i.e. material color (I can create a node group with exposed socket if that helps), without having to link in and maintain geometry of two variations?

Intended workflow:

  1. Somebody not familiar with the setup copies the masterfile to project.
  2. Project requires a white version of ThatThing, which he will find under “insert group instance”.
  3. I can maintain the original black version of ThatThing with new geometry and materials.

Is it possible in masterfile to define a color or variable which is passed on to the materialsystem of the linked in group instance so that it renders with the correct color suiting that project? User only has to change this variable to get new visuals. End intention is to keep it simple for end user and minimize filesize and memory requirements. Some objects will be appended to masterfile because geometry will have to change based on project.