Probably everything BUT butter rum.....
Yeah.. I do agree with birdy.. I would really check some of the
juice visually.. make sure it is uniform in color and not green in color in some areas..
If you feel that it taste that way because of some breakdown.. contact the vendor and seak a refund or replacement.. and , If you think it just is standing up to the flavor over all but is still good.. just think of complimentary flavors to the pinacolada drink itself... maybe some caramel, butter-rum, apple, strawberry might be a stretch, cherry, even pineapple... so many to name .. I don't know what you have .. but you could even take a little of the pin colada juice.. take a small dropper bottle..if you have one... and mix a small amount of it with some cherry juice or pineapple juice .. I wouldn't go too far with the juice maybe 60% pina colada to 40% fruit juice.. Try that and see if it helps..
If it does , order you some doublers of concentrated flavors to add to that pinacolada and have a feild day.
Tom