My guess is that red hair comes from Diannas stableman ...that pregnancy was a great way to return Charles infidelity to him
Diana’s brother, Charles Spencer, once gave a tour of the family’s ancestral home on his estate. It aired on public television a number of years ago.
In one room, there were a number of gigantic paintings of the male ancestors of Charles Spencer and Harry, and a great many of them had red hair.
Just saying.....