Left: Diana, Princess of Wales wears a pink polka dot dress by Donald Campbell at the Perth Hockey Stadium in Bentley, Perth, Western Australia, on April 7, 1983. Right: The Duchess of Cambridge wears vintage 1980s Oscar de la Renta to visit the Museum of Literature Ireland in Dublin on Wednesday, March 4. Getty Images 

Kate Middleton wears 1980s vintage dress that looks like something Princess Diana would have worn