Emily Blunt doubled down on Valentino’s Rockstud revival on Friday in London, stepping into a red version of the studded sandal she had worn in black just one day earlier. Emily Blunt wears a pair of red Valentino Rockstud Sandals as she attended the UK Photocall of “The Devil Wears Prada 2” at the V&A South Kensington, London on Friday. Jeff Spicer/Getty Images for The Walt Disney Company Limited At the U.K. photocall for “The Devil Wears Prada 2” at the V&A South Kensington, Blunt wore Valentino Garavani’s Rockstud Kidskin Sandal, a 100 mm red leather style with an open toe, a narrow stiletto heel and an adjustable ankle strap. Platinum-finish studs of different sizes traced the front band and straps, giving the sandal a lighter, more open read than the caged Rockstud pumps that dominated the 2010s, while keeping the house code clear. A closer look at Emily Blunt ’s red Valentino Rockstud Sandals .…