The fuchsia Seraphine Maternity dress that Kate Middleton is seen wearing in her first royal family portrait with Prince William and newborn baby Prince George has sold out.

The dress Middleton wore in the family portrait sold out from Seraphine Maternity less than 24 hours after the photos were released.  If customers try to buy the popular dress online, a pop-up appears stating, "Due to high popularity of this style, please be advised that orders will be dispatched the week commencing 16th of September."

For just $79, customers were once able to purchase the "Jolene" dress. It features a draping front that leads into a knot and a deep-v neckline which "pulls aside for breastfeeding," according to the web site.

"The Kate effect is huge, and we have been enjoying a 400% growth in sales since it became public that Kate bought Seraphine dresses back in April 2013," Cecile Reinaud, president of Seraphine Maternity, said in an interview with Hello! magazine.

The web site also features three additional dresses worn by the Duchess of Cambridge, which are clearly labeled as "Worn by Kate Middleton" on Seraphine Maternity's web site.

Two portraits of the royal family were released Monday via the Kensington Palace. The pictures were taken in early August by Kate's father, Michael Middleton. The scenery was the family's temporary residence in Bucklebury, England. The royal family will stay at the Bucklebury estate until they move to their permanent residence, Kensington Palace in London.

In one photo, Kate, or Catherine, is shown hold holding her son Prince George Alexander Louis, who is almost one month old. They are joined by Prince William as well as their two dogs: an adopted cocker spaniel named Lupo and a retriever named Tilly. A bright background surrounds them along with grass, hedges and trees.

View the royal family's latest portraits here.