When the sun starts to go down a little earlier, and the sky starts to look a little bit grayer, bold pops of color are not only welcome, they're essential to our wardrobe's vitality. And this season, we've got our eye on one stunner of a hue: cobalt. Because who doesn't love a bright blue? From printed trousers and structured sheath dresses to gorgeous leathers and wools, cobalt blue is all over our fall-shopping wish lists.