Oghma Infinium

As long as Oghma Infinium is untapped, whenever you choose to put one or more cards on the bottom of your library while scrying, you may pay {u/b}{u/b} if you do, you may cast up to one of those cards this turn
{u}{u}{t}: Exile target card in a graveyard, you may spend mana as though it were mana of any color to cast it this turn