On one of the first hot, summer-weather evenings of the season in Washington, Michelle Obama turned up the glamour with her dress choice for Tuesday night's state dinner at the White House in honor of German Chancellor Angela Merkel

Mrs. Obama shimmered in an all-over embellished gown by Naeem Khan. It was an ivory, V-neck column dress embellished with silver beads, white sequins and metallic thread in a geometric pattern — and she's back to what seems like her favorite seasonal sleeveless look, which shows off her famously toned arms.

Khan also designed the gown Mrs. Obama wore to the first state dinner she and President Barack Obama hosted for the Indian prime minister in 2009. Thursday's look, in fact, was reminiscent of that outfit — which was considered a style success.

She accessorized with gold bangle bracelets by Alexis Bittar.

"You know she's going to make fashion statement — and you know it's going to be quirky or a little flamboyant — but it matches her vibrant and joyful personality," said fashion commentator Mary Alice Stephenson, who consults for Khan and helps style the designer's runway shows. "It's happy fashion. You want to look at it."

Stephenson said Khan is a good choice for Mrs. Obama because he can convey sophistication without losing a little wink and nod to the fantasy of fashion. "Like Mrs. Obama, his clothes are alive. ... They're classics but tweaked."

His signature beading provides the exclamation point that Mrs. Obama likes to add to her outfits, Stephenson said.

White looks regal on the first lady — especially on an otherwise clean silhouette, she said.

Mrs. Obama also wore a white Tom Ford gown last month in London when attending a formal dinner hosted by Queen Elizabeth II.

Most of the guests to this state dinner, to be held in the Rose Garden, wore more standard-issue black, gray and deep blue instead. The exception was House Democratic Leader Nancy Pelosi, who pulled a two-piece white Thierry Mugler from her closet.

"Very old," she said.

Associated Press writers Nancy Benac and Darlene Superville in Washington contributed to this report.