Dress:

The base of Michelle's feminine look is a dress with an oversized blue and green floral print. Though Michelle's dress appears to have straps, she layers a cardigan over it -- so you can achieve a similar result with a strapless dress like the Flower Crush in purple from Lulus.
$32 from Lulus.com

Cardigan:

Michelle complements the blues and greens of her dress with a vibrant yellow short-sleeve cardigan, which  makes all of the colors in her outfit pop. This featherweight cashmere short-sleeve cardigan in light chartreuse from J. Crew is a sophisticated shade of yellow and features adorably subtle ruffled trim. Best of all, this ultra-lightweight cashmere lets you cover up your shoulders without feeling like you're piling on an extra layer.
$49.99 (on sale from $148) from JCrew.com