Charcoal floor tiles, a concrete-look wall and a dark timber vanity: gunmetal tapware belongs in that kind of room. It is a deep brushed grey that sits between brushed nickel and black, so it gives an industrial edge without the hard outline a black tap draws.
Gunmetal works best where the room is already moody. Think dark ensuites, powder rooms with feature lighting, and bathrooms built around grey stone. In a bright white bathroom it becomes the accent, so repeat it on the shower and the towel rail to make it look intentional. Dark finishes can look flat under cool downlights, so judge the colour in natural light where you can. Gunmetal also pairs well with brushed nickel accents for a layered, two-tone grey look.