In the shared photo series, the 35-year-old actress and former American Idol contestant is posing for press photographers in the mock turtleneck floor-length halter dress that includes an elegant train. Katharine paired the dress with jeweled drop earrings.
While the first couple of photos are framed to show off her gown, the fourth -- a selfie -- gives the viewer a close-up of her makeup. Katharine opted for dark eyeliner and mascara with shimmery pink eyeshadow, plus some pink lipstick.
Her hair, which falls past her shoulders when down, has been tied into a sleek high ponytail. In the series' second photo, you can see that she also chose to carry a silver clutch purse with her.
As Daily Mail reports, Katharine wore the outfit to The Breakthrough Prize awards, a yearly ceremony that celebrates achievements in science. The third photo of her Instagram post reveals that she attended the event with her husband, David Foster, who kept his fashion choices simple with a classic black tuxedo.
In the comments section, Katharine received loads of compliments about her look, and some of those comments came from fellow celebrities."You are so pretty," wrote Lisa Rinna, actress and cast member on The Real Housewives Of Beverly Hills.
But Katharine's non-famous fans chimed in as well.
"The dress is amazing!! That color really suits you," one fan added.
"You look stunning that dress color is so delicate and beautiful!" another commented.
"Hey you're the most beautiful girl in the world," a third gushed.
In her post, Katharine tagged the team responsible for her stunning ensemble, revealing that the dress was designed by former Project Runway winner, Christian Siriano. The earrings are from Swarovski.
On her Instagram page, Katharine's makeup artist, Amy Clarke, shared a behind-the-scenes glimpse of how the actress' glam squad worked their magic. In the photo, Katharine is wearing a floral-print robe, as her ponytail is perfected by hairstylist Eduardo Ponce.
You can also see a number of beauty products in the background. Amy disclosed that she used items from brands like Tatcha, ReFa USA, Senna Cosmetics, and Ardell Beauty to elevate Katharine's natural good looks.
"@Katharinefoster is a goddess," Amy wrote on Instagram over a photo of Katharine in the blue dress.Based on the feedback she's getting on her most recent Instagram photo, it's clear that lots of the actress' fans agree.