Hewitt.. Resemblence mre than just red hair
there are rumors that diana had an affair with John Mcenroe before Hewitt. Someone posted some pics of young John that did resemble Harry.
Even if Harry is someone else’s kid there is no way the RF can go back on it now that Charles is the dad.
But given how many mental issues the Royal Family has had in the past Harry is is probably Charles kid..and a nutjob.
Relationship didn’t begin until long after H’s birth.