Yes, stainless steel can develop rust-coloured spots and discolouration despite its name. Often, these are caused by airborne iron particles settling on the surface and corroding. Small brown marks do not necessarily mean that the stainless steel itself is corroding.
Salt deposits, accumulated dirt and cleaning with steel wool can also cause discolouration. Stainless steel has a protective surface layer that can reform when the surface is kept clean, so clean as needed and remove marks promptly. In coastal areas, AISI 316 or 316L stainless steel is often used. Stainless steel resists corrosion but is not completely immune to it.
