Stripped front door

Hi all today I have stripped my door ready for sand fill prime etc.
I have decided after revealing the original front door that it's to nice to paint
I have been advise to use tung oil as oak can go black if not treated properly.
Is this the normal procedure for staining me protecting a front door that will be left as wood?

Thank all

Tung Oil will do the job. Personally, I have just always used either Sikkens or Sadolin. I believe Oak should only go black if left unprotected or if it has anything other than brass or stainless steel fixings in it.