When working on bigger projects, you have a lot of paint samples, even if they are sometimes only used once in your model. Users should be able to create “folders” or “tags” for the multitude of paints. This way, for example, when I am working on the exterior of my model, I have a folder/tag for “exterior” with the stucco, wood, grass etc. This will seperate the exterior paint samples from each one in different rooms.
I think tags might be better, since some materials like white, black, some woods, and metal will exist in different places in your model.