Still having some issues so I wanted to provide a bit more in the way of detailed information as to what I'm looking to do.
What I did was take the base map and saved it as a paint document then I opened the map as the "background" layer in Paint.net. I saved it in a paint document as if I just open the map itself in Paint.net I get a checkered background.
I then opened the next layer which is state boundaries, then I opened the counties as another layer, and finally cities as the final layer.
What I'm looking to be able to do is when I add another layer (which would be placed below the cities layer so the paint is behind the city labels) and start coloring the map I want to just color within the United States...so for example, I could put the painbrush over Canada and no color would result...same thing with the Great Lakes.
I would do the same process as described above, but with a United States map and I want to be able to color only the United States...so if I put the brush over the Pacific or Atlantic or anything that wasn't within the US no color would show.
Doing this would make creating colored maps super easy b/c I would have to waste time going carefully around the edge.
I've tried the magic wand tool, but for some reason it doesn't seem to work clearly. I'm pretty sure there is a different way to do what I'm looking for. When someone directed me to the program years ago they sent me a base map. They mentioned something about by opening it in a certain format or way that if I colored it, it would only color within a specific boundary (it was a map of the Northeast so it would only color the Northeast and not over the Atlantic).