The Blonde lady is Anne Widdecombe a conservative politician and convert to Catholicism. The Black Guy is John Sentamu I think, the Anglican Archbishop of York - not too sure though.
Do not forget also that Fry is Jewish by birth and homosexual, which is quite germane to the discussion, homosexuality being anathema to the Catholic Church.
Fry's wit, humanity and intellect are shown to great effect here, his arguments are quite incontrovertible, that is why faith is so useful.
David