I have a scanned map of the US in pdf that, in addition to state boundaries, has "delivery territories." These territories are exclusive areas within the US where different companies deliver their products. The boundaries of these territories may cross state lines (covering at least part of two or more states), or they may be contained within a state. These boundaries are defined at the zip code level.
I have already georeferenced the pdf map and if I overlap a shapefile of zip codes, the boundaries of the territories match the boundaries of the zip codes (though territories cover many zip codes, and often a complete state or more). What I want to do is to recover the information about delivery territories from this map. Is there a way to do this? In the map, state boundaries are represented using red lines, while delivery territories are represented using black lines. I can't post the map online because of copyright issues, but I got the following map online that represents a similar setting. In this setting, I would like to recover the territories, for example, at the zip code level, that correspond to each color (in my case, a different color would represent a different company)
Edit: My map is a white map with only the boundaries in color (red and black). The map below would be very similar to mine if instead of colors representing different areas, it only had the boundaries.