Head-to-toe, monochromatic dressing is a fool-proof way to assemble an outfit—simply pick a color and stick with it. This week, Gigi Hadid wore a full periwinkle blue ensemble to sister Bella's 21st birthday, complete with matching heels, while Rihanna recently celebrated the launch of Fenty Beauty in a yellow ballgown skirt and matching sweater. Of course, the more color-adverse can still get on the trend: look no further than cool girls Adwoa Aboah and Kristen Stewart, who each took on the look in all-white ensembles. Here, a look at Tilda Swinton, Laura Dern, Adriana Lima and more of the best monochromatic looks to hit the carpet.