This morning, as commuters across London wrestled with umbrellas beneath what felt like months’s worth of rainfall, we were forced to admit it: summer is over. For some, the changing of the seasons signals the return of back-to-school dressing; for parents and reluctant pupils alike, however, it means the real thing. But what does one wear for that all-important September drop-off? The Princess of Wales, for one, is keeping things classic.

Photographed accompanying Prince George to Eton College for the start of his first term this morning, the Princess made a case for one of autumn’s richest shades in a leafy-green Emilia Wickstead dress. The colour has long been a favourite in Catherine’s wardrobe: she recently attended Wimbledon in a similarly hued wool-crepe midi dress, also by Wickstead, wore a verdant Ralph Lauren blazer to this year’s Commonwealth Games, and chose an emerald Alexander McQueen coat for the Irish Guards’s St Patrick’s Day Parade in March.

For Prince William, though, the occasion marked something of a full-circle moment: his 13-year-old son was embarking on the same journey he had 31 years earlier, when Princess Diana accompanied him on his own first day at Eton, where he studied from 1995 to 2000. Though Catherine and Diana have shared more than a few style parallels over the years, the Princess did not echo the ocean-blue tailoring worn by her late mother-in-law on that same day. The darker palette did, however, feel particularly well suited to this morning’s autumnal turn.