forty years to go March 25, 1983 when the Princess of Wales repeated her wedding going-away outfit in Canberra during her first Australian tour. The pale coral Bellville Sassoon suit and John Boyd tricorn hat with that marvelous ombre dyed plume combined for such a memorable look.
Embed from Getty Images
Embed from Getty Images
Images from Getty as indicated
Royal Hats 
An iconic look. Really pretty, but thankfully she edited her style significantly later on. Can you imagine a 21 year old woman wearing anything like this now?
Not much to add to this, but:
https://www.yahoo.com/lifestyle/fascinating-story-behind-princess-dianas-140000235.html
First in a collection of wonderful similarly shaped hats – thanks for the memory!
It seems like yesterday that the Princess first toured our country. She looked so lovely, her suit was gorgeous. Loved her hat.