Since launching in 2016, the series has grown into one of the biggest hits on the streamer, charting the history of the British royal family over several decades.
At the heart of the most recent season was the difficult relationship between Queen Elizabeth II (Olivia Colman) and her sister, Princess Margaret (Helena Bonham Carter).
After earning an Emmy nomination for her work on the series, costume designer Amy Roberts spoke to The Hollywood Reporter about how that was reflected in the stylish outfits seen on the show.
"This is like a fairy story: You've got the good sister and the bad sister, the handsome prince and the beautiful princess coming up later, and the idea behind that for me was always to almost colour-code our characters," she said.
"Colour — '60s, '70s colour — was our mainstay. For the queen, it's those clear pastel, sugary colours, and then you've got Margaret in those sorts of slightly more subdued aubergines, olive greens, that kind of bruised element to her.
"Margaret has no particular role [in the monarchy], so we were trying to say that in colour, in slightly more frenetic patterns, a kind of throwaway-ness about her: trying on fur coats by the swimming pool, constantly smoking and hiding behind sunglasses."
Roberts went on to explain how she doesn't stick rigidly to the clothes that the royals wore in real life at that time, arguing it's better to be "completely creative" with wardrobe choices as "it's not a documentary."
Earlier this year, the series was announced to be ending with its fifth season, but this decision was later reversed to include an additional sixth season of The Crown to wrap up the story.
Colman will return one more time as Queen Elizabeth II, before passing the baton to Imelda Staunton for the final chapters of the series - just as Claire Foy did before her.