In 500 words or less... How do you covert your wall colors back

[amddrafting]

So while playing with some wall colors I used the spray tool and now I can not get the default wall material to return to normal.

I've added a pony wall to the bottom and it is the same color as the walls even though it's stone. When I disconnected the wall to make the porch no longer a room the wall returned to their default state but as soon as I drew the wall again it returned to the sprayed color.

I've always had issues with this in the past but never knew how to fix it. Now I have to. Any help would be appreciated.