Rowling opted for the less structured, pink and green version, teamed with pale pink accessories and a chic updo while Rihanna went for the red rose design (perhaps to match her hair?).
There's no denying that RiRi looked fab in her cleavage-boosting version; she knows how to make a statement and she did exactly that in the gorgeous gown. However, the pink and green colour combination is far more suited to Rowling. So who looked the best? Let us know by voting below.