I dug a 3 prong yesterday with the main root similar in color as the red colored one that the O.P. dug. The other portion of the root which grew off the main root was completely normal colored. The root was dug out of high mountain black soil which runs very deep in this area and is on a Northwest facing slope. When I washed the roots, I rubbed on the reddish colored portion of the root and much of the color actually came off and revealed a normal colored root underneath. I did not know what to make of it until I saw the pic of kentuckyhilldigger's root but now believe that it may be a protection mechanism of Ginseng to protect or heal from a disease or fungi. There have been several fast moving flash wildfires in this area over the last 5 to 20 years but mainly on the South facing slopes, so is it possible that the main root got a little scorched during one of these wildfires, I don't know??!! Otherwise, there is no other explanation as to why the root I dug would have a reddish color or coating on the outside of the main root with the exception of it being a protection mechanism since the soil it was dug from was totally rich black mountain soil. It would be great to have such a root studied in a Lab to find out if this is the case!
Note: I cropped a picture of roots I dug yesterday and have included a pic of this specific root. As you can see, portions of the root still has some of the reddish color while you can see that other portions are normally colored where I rubbed it while washing it.
Frank