While I am NOT historian, of any type, I do have a special spot in my heart, for the SP line of revolvers. I am not aware of any SP's, being made in 'blue'.
Never one produced in blued carbon steel that I'm aware of. Currently there is a TALO exclusive which is stainless with a black cerakote finish. It looks like a blued revolver but much more durable and rust resistant than blued carbon steel.