Material Separator Help?

My goal is to create a script that finds all the materials of every brick in my game and then divide them up by Material and a child of that being the colors.

The point of this is so that it makes my life massively easier when exporting models for 3D art. I keep trying to figure this out but am struggling so a full solution would be invaluable.

Understanding how to find all the children and children of children, etc has confused me. I need to be able to find the single part within a model with 100 parents and divide them up based on material, then color. Thank you!