Naomi Ackie's chartreuse Valentino gown with that caped shoulder detail is a look that lives in our minds rent free. It's a great example of an elegant, modest gown with a beautiful colour that speaks for itself. The shade of green is like a very grown up version of the trendy slime green that has become the unofficial colour of contemporary street style — and my oh my, does Valentino's creative director Pierpaolo Piccioli know how to create a stunning, modern evening gown.