Hello, what I have noticed on my particular set, red is too bright and orangy on Auto Color Space and Blue is towards Purple, Bluish-Purple. Green is Yellowish.
If I switch it to Custom without any variables entered in, red get's less bright and appears more red, blue looks blue, Green also looks more greenish. The secondaries appear different two but harder to tell using color bars to see the changes when switching Auto, to Custom. Native I don't really use. This is just visual observations not using a meter. Currently I don't own one.