Aside from her extremely strong diamond ring game, birthday girl RiRi sure knows how to give damn-good b-day mani. And of course her heavy metal aubergine nails are on point for AW15. The NYFW catwalks were awash with metallics, from New York label Honor's cold, hard, shiny colors (think bashed-up pipes, industrial steel and school-dinner cutlery), to Lena Dunham-endorsed brand Creatures Of The Wind's bold blues with rough matte details. Good news if intricate manicures are just not your forte, because you can nail this on the first try. Trust.