Elizabeth Debicki as Diana wears vintage Versace sunglasses in Season 6 of The Crown.
The glasses seems to be the Versace model 527, probably in Tortoise (code 900) but possibly Black. The frame has small oval lenses and the two large, round gold Medusa logos on the temples.
The Versace sunglasses can be see in Season 6, Episode 1 which takes place in the year 1997. This model is period correct.