The dress was a cream Roland Mouret gown that Kate Middleton previously wore to a private dinner back in May 2012. While she accessorized it with a silver clutch and strappy sandals last year, this time she wore it with black pumps and a matching black clutch.
Middleton topped it all off with a $35 Zara necklace and a low ponytail.
While the duke and duchess attended the premiere, William addressed the death of South Africa's first black president with a statement.
"It's extremely sad and tragic news, we're just reminded what an extraordinary and inspiring man Nelson Mandela was," Prince William told reporters in the halls of the Odeon theater. "Our thoughts and prayers are with him, and with his family right now."