One of the high tech companies I worked for as a production control manager had a sheet metal subsidiary, so I saw raw cold rolled (CRS)and hot rolled (HRS) steel and the parts made from them. Depending on thickness, CRS that was supplied as a roll or from flat plates were a medium metallic gray, HRS was darker. Even after stamping, CRS retains its gray color, which is what hood hinges are made from. The stamping process utilized a special oil as a lubricant to reduce wear on the tooling. The oil was not removed as it was also a rust inhibitor. After parts were assembled, some moving, many more welded together, the assemblies that were to be painted were dipped in solvent to clean them. Parts to be zinc plated were dipped in an acid bath prior to plating by the plating subcontractor. I cannot remember if any of the parts we produced were phosphated. A sample of the gray metallic color would be the steel bars sold at Home Depot. Springs, by the process that makes them, are heat treated steel and are very dark, almost black, also oily. A light phosphate finish is about as close as you can come to parts made from CRS. Be advised that an oily part attracts dust.
Jim