Warm grays contain underlying beige, brown, or green undertones — they read as earthy and approachable. Cool grays, like Nickel Grey, contain blue or silver undertones that give them a clean, precise, metallic quality. The distinction matters significantly for room compatibility: Nickel Grey pairs naturally with cool-toned spaces featuring stainless steel, chrome, concrete, and white gloss surfaces, while warm grays perform better in rooms with timber, cream, and organic-toned materials. Seeing a fabric swatch in your actual space before ordering is always recommended.