Last fall’s black nails may have fallen out of style, but you’re not ready to go pastel — what to do? You can still go dark with the newest trend in nail color: navy blue. The inky shade has already been spotted on stylish celebs from Eva Mendes to Fergie. To pull off this edgy look, you’ll need to follow a few simple rules. Keep nails short and well manicured — long talons can look Halloween-appropriate dipped in dark blue, and chipped dark polish is best left for punk rockers. To ensure long-lasting color, first apply a good base coat like Creative Nail Design Stickey Base Coat, $7; at ulta.com. Then snag a navy polish like Lippmann Collection Nail Lacquer in Rehab, $15 at lippmancollection.com or the shimmery Revlon Dark Pleasures Nail Lacquer in Midnight Affair, $7 at drugstore.com. Then, seal the color in with a top coat like Seche Vite, $10 at drugstore.com, and you’re set for fall!