"Olive" could mean something more than the color of his skin. Others in St. Malachy's prophecy included elements from the Pope's family coat of arms, for example.
In this photo released by the German Catholic News Agency KNA and dated from July, 8, 1951 Joseph Ratzinger, standing right, is seen with his family, father Josef, mother Maria and sister Maria, seated from right, and brother Georg following their ordination to the priesthood. Cardinal Joseph Ratzinger of Germany, a longtime guardian of doctrinal orthodoxy, was elected the new pope Tuesday April 19, 2005 in the first Roman Catholic conclave of the new millennium. He chose the name Pope Benedict XVI
Do any of the symbols that you suggest signify "olive" here?
I guess if one digs deep and wide enough, one can find something to prop up any prophecy.