The Peruvian Inca Sweater and fashion designer Benny Ong along with Benetton gave her that signature look. Note the open back Benetton T shirt above she bought in the London store in 1983 pictured above.
Ong designed her walkabout dress for The Ayer’s Rock tour in Australia. The white dress was part of his Sunday Sketches Collection. Royal Fashion was all the rage in August 1983 fashion magazines in the UK and worldwide. One such magazine cover is here in this post