Long hemline? Check. Modest? Check. More jewels? Check.

For her first official outing of 2014, the Duchess of Cambridge met all the requirements under her new dress code rules set forth by Queen Elizabeth II. She wore a blue silk gown with a V-neck by Jenny Packham, and she borrowed some of the Queen's jewels to finish off the look. Her signature waves were also on display at the National Portrait Gallery's Portrait Gala on Tuesday night.

The first time she wore this Jenny Packham dress back in October to the 100 Women in Hedge Funds Gala, she wore very minimal jewelry, exposing her décolletage and making for a much sexier outfit.

This time she wore a necklace given to the Queen by Nizam of Hyderabad as a wedding gift, the Mirror reports. And as if the evening couldn't get more posh, the red carpet was actually a golden staircase.

Middleton was joined by artists and people in show business, such as Liz Hurley, according to the Mirror. She saw the "pen portraits," which are "exclusive stories, descriptions and commentaries about a chosen painting in the gallery's collection," that were being sold to raise money for the gallery's research and to help purchase "portraits of national importance."

One of the attendees was Hilary Mantel, an author who called the Duchess "a plastic princess" that was only good for giving birth.

Middleton made a short speech at the event thanking people for attending and praising the gallery.

"The Gallery's achievements are exceptional," she said. "The holy the most extensive collection of portraits in the world, and their unique and brilliant exhibitions never fail to inspire us all."

But the ultimate winner of the day was Jenny Packham, who also showed her collection at New York Fashion Week that day.