LEFT: A Diane von Furstenberg design for her spring 2011 fashion show in September, in New York. CENTER: Designs by Junya Watanabe from the line’s Ready To Wear Spring/Summer 2011 collection in October, in Paris. RIGHT: A design by Emanuel Ungaro for his Ready To Wear Spring/Summer 2011 fashion show, in Paris.

PARIS — Nearly a month ago, back in New York at the start of the spring fashion season, the young designer Prabal Gurung said during a preview of his collection that he wanted to make a statement against the too-tight minidresses that have dominated runways for the last several years. His dresses were a uniform mid-calf length, which, at the time, looked a little dowdy. In retrospect, they now seem prescient.

Over 28 days and hundreds of collections shown in four cities, the most obvious message from the spring fashion shows, which ended earlier this month, was a dropping of hemlines — in many cases all the way to the floor.

And yet for all the associations with modesty that long imparts, you could not say that this has been a conservative season, not with the orgy of color and prints or, paradoxically, so many clothes that were sheer to the point of invisibility. Rather, the season was the powerful game changer that retailers and editors have been hoping for — if only to give customers a new reason to shop.

“Isn’t that what we all want to see?” said Amy Astley, editor of Teen Vogue, on Tuesday morning, just before the tour-de-force Chanel presentation held here under the big glass ceiling of the Grand Palais. That collection alone, shown on a French garden set to rival Versailles, could have the effect of making people want to shop again, touching as it did on the season’s big trends of color, romanticism, transparency, longer lengths (with shorter options for those who aren’t quite ready) and, most fortunately, wearable footwear.

“I like the fact that if you wear a long, floor-grazing skirt in the daytime, you won’t look strange,” Astley said. “Or goth.”

Direction for spring

The new direction for spring, in fact, owed a debt to an exhibition that took place just across the street in March, a retrospective of the career of Yves Saint Laurent, whose clashing color combinations (yellow, pink and orange), animal prints, tuxedo jackets and ruffled peasant skirts were modernized in collections as diverse as Marc Jacobs in New York, Ferragamo in Milan and, in Paris, the Saint Laurent show of Stefano Pilati. It was a brilliant season — not quite perfect, but with enough high notes and drama to merit a comparison to the opera — sort of fitting when you recall that New York’s Fashion Week kicked things off last month with shows for the first time in Lincoln Center.

“This season is not just about party dressing,” said Marilyn Blaszka, riding in a cab to the Celine show at a tennis club in a fancy part of town.

“Maybe the party’s over, and reality is beginning to set in,” said Dominic Marcheschi, her partner in the Chicago store Blake.

You could hear the relief in their voices. The longer skirt lengths and more forgiving jacket cuts with looser shoulders, like Miuccia Prada’s, are easier to wear, and sell, than clothes that are just about sex. This season, for the first time, Blake bought the Versace collection, with its graphic lines and mature proportions, if that tells you anything.

The shapes of the season followed two diverging paths: the super-clean lines at the attention-grabbing Jil Sander show and the sharp dresses at Calvin Klein representing one side; the long, fluid lingerie-like dresses at Bottega Veneta, Stella McCartney and Narciso Rodriguez on the other. (Shorter skirts could still be found at Giambattista Valli, Pucci and Isabel Marant, and Astley predicted that the longer lengths could take a few seasons to really catch on, so don’t give up that gym membership just yet.)

“On one hand, there is a certain amount of sobriety in the collections,” Roberta Myers, the editor of Elle, said. “On the other, there is a lot of movement, especially around the floor.”

Bold colors are back

The bold colors defining Milan and Paris were preceded by shows in New York more often characterized by white, cream and neutral tones (at Thakoon, Alexander Wang and Donna Karan). Perhaps they were a palate cleanser, but either way, Raf Simons’ electric tones at Jil Sander were like a revelation, and the designers who followed joined the choir.

“I feel a real sense of optimism here,” said Linda Fargo, the fashion director of Bergdorf Goodman. “Color, for me, indicates that in a big way.”

It was striking to see those jarring pink-and-orange combos at a number of shows: Martin Grant, Yves Saint Laurent, Cacharel, Giles Deacon, Christopher Kane and Marc Jacobs. (Not buying it was Karl Lagerfeld, who, at the Chanel show, told Cathy Horyn of The Times: “I really don’t think women want to go around looking like a Saint Laurent shopping bag.”) Regardless, it made last fall’s foray into minimalism feel like just a blip on the fashion radar.

“After the Celine-ification of fashion, everything became about good taste and beige,” said Mickey Boardman, the editorial director of Paper magazine, referring to the widespread camel-coat craze initiated by that label’s designer, Phoebe Philo. “I think we all hungered for hot pink.”

Another glaring addition: Wild and colorful prints have been a phenomenon in Europe, beginning with Prada’s amusing dresses with ornery little monkeys climbing up the side. Akris offered an array of wild orchids; Missoni incorporated rock lyrics with zigzags; and Stella McCartney worked a zesty citrus theme of oranges and lemons.

There were also mini-trends throughout the shows. A softer use of color came in the new tweeds that appeared here and there, most beguilingly at Proenza Schouler in New York. Deacon, at his Ungaro show, translated the house’s signature fuchsia in tweed; and Oscar de la Renta, of course, had his own witty takes.

In Paris, there were bursts of punk, at Balenciaga, Balmain and Jean Paul Gaultier, and a psychedelic trip from Yohji Yamamoto that played on earlier touches of luxury hippie-wear from Michael Kors in New York and Pucci in Milan.