Tunic - Zara | Tights - M&S | Boots - Kurt Geiger | Detachable collar - ASOS
As an aside, navy & black? I love it! I know a lot of my friends would be turning in their graves just thinking of pairing navy & black together. Throw away the rules! What 'shouldn't' work (according to who?) just might work better than you think. Are there any style 'rules' that you love to break?