There were at least three types of SP passenger cars with silver sides and a red stripe at the top:
- Genuine Budd stainless steel cars with fluted siding, built in 1950 for the Sunset
- Re-sided Pullman-Standard Daylight cars with flat stainless steel exteriors
- Other cars from the City of San Francisco and the Lark, with painted steel sides
- A few heavyweight head-end cars that made the cut.
Southern Pacific began using red and grey instead of red and orange (or black widow) on its passenger diesels beginning in 1959 or '60, and they all went grey as fast as they could be repainted. SP treated its passenger engines better than it did the passengers. The passenger engines were highly maintained and very clean.
