by soosy
Colony: "Buy Goods +2 at this region."Caravan Driver: "During a buy action, you may also buy goods from the supply for 6 gold each. Place these goods in your province warehouse. Sell Goods +2. Buy Goods +2."
I'd actually say none have to be from the island and all 6 could be from the bank. I interpret the Colony ability just to modify any Buy Goods action while you are at the island. I don't see it as saying 2 of the goods have to be from the island.