Sunday, May 5, 2013 at 7:51 PM 
Mrs. O spoke at the Department of Agriculture in Washington, D.C. on Friday. For the appearance, Mrs. O wore a colorblock Preen Pre-Fall 2012 dress, previously seen here in 2012.
Preen Wednesday, April 10, 2013 at 8:45 PM 
As part of the "In Performance at the White House" series, Mrs. O hosted musicians and performers for a Memphis Soul workshop yesterday. Middle and high school students also took part in the interactive, daytime event.
For the evening portion of the program, there were performances by Alabama Shakes, William Bell, Steve Cropper, Eddie Floyd, Ben Harper, Queen Latifah, Cyndi Lauper, Joshua Ledet, Sam Moore, Charlie Musselwhite, Mavis Staples and Justin Timberlake, with musical direction by Booker T. Jones.
Plus, there was quite a fashion crowd! Designers Jenna Lyons, Prabal Gurung, Rachel Roy, Bibhu Mohapatra were all in attendance, as was Tracy Smith, owner of House of Lavande, and Mary Alice Stephenson, stylist and beauty expert. What message is in the mix?
On the style front: For the daytime event, Mrs. O embraced bold color, wearing a yellow pantsuit with a pink blouse and gold necklace. For evening, the First Lady opted for a one shoulder black gown, seen here (thank a MI Mom!).
Update: Thanks to Charlene in Detroit, who identified Mrs. O's suit as Preen from Spring 2012, seen here. The First Lady previously wore the jacket with a Preen dress in June 2012, here.
Preen Wednesday, October 3, 2012 at 9:42 PM 
For the first presidential debate this evening, Mrs. O wears a dress and jacket from Preen. The look is from Justin Thornton and Thea Bregazzi's Fall 2011 collection, seen here, and previously worn by the first lady here and here. The multicolored geometric-floral prints used in this collection were reported to be inpsired by the Northern California Arts and Crafts movement.
Preen Tuesday, June 5, 2012 at 4:43 PM 
It's been a full day for the First Lady. This morning, wearing a Preen pixel print dress paired with a honeydew hued jacket, Mrs. O joined Walt Disney Company Chairman and CEO Robert A. Iger to announce that Disney will introduce new standards for food advertising on programming targeting kids and families.
Next up was an interview with the Associated Press to promote the publication of the First Lady's new book, American Grown. For the occasion, Mrs. O wore an ombre blue floral shirt dress paired with a belt and cardigan. Very "ladylike with a twist" on both occasions!
"First Lady Joins the Walt Disney Company to Announce New Standards for Food Advertising to Kids" [White House]
Update: In the second photo, Mrs. O wears the Boy. by Band of Outsiders Degrade Toile de Joie Dress. A trench coat version of the dress can be seen here.
Boy. by Band of Outsiders, Preen Tuesday, May 1, 2012 at 11:45 AM 
The First Lady attended the opening ceremony for the Warrior Games at the Olympic Training Center in Colorado Springs, Colorado yesterday. On the style front, Mrs. O turned to one of her classic shilouettes, the sheath dress, updated for spring in a colorblock meets patchwork pattern. Blue heels completed the look, which practically projects fun and cheer!
Update: While the designer has not yet been confirmed, reader Charlene in Detroit observes similarity to the pastel pixel print featured in the Preen Spring 2012 collection, seen here. Red Carpet Fashion Awards also credits the dress as Preen.
Preen