Undo material painter

[dsauder]

I was trying to change wall colors and think I ended up changing some of them with the material painter. Now that this is done, I can't figure out how to "un-do" that. Walls that were never "painted" I can change from one type of wall to another and the exterior view and rendering will update to reflect the different material. Walls that were painted can not be changed at all by changing the wall type.

For example, I have walls of two different shades and widths of vinyl clapboard siding now. Walls of one shade, I can change to stucco or brick. The walls of the other shade cannot be changed at all.

Any ideas how to fix this or what I might have accidentally done and how it can be undone?

[Katalyst777]

Article Number 162: How to restore materials that were changed using the Material Painter