Well, Mr. Norman and I have argued about this in other posts, but in my memory the Seaboard's "Silver Service" trains never carried anything but stainless steel cars. In the winter, cars from Santa Fe and cars with "California Zephyr" letterboards were fairly common, and I believe I remember at least one New York Central stainless steel Pullman. On one trip, our rooms were in a Nickel Plate Road 10-6 car, and I didn't even know what the Nickel Plate Road was, or where it ran.
The ACL trains carried a dog's breakfast of Pullmans from almost anyway. PRR Tuscan red "Imperial" series cars were quite common. I and my sisters liked those because they had small upper-berth windows. I also remember a UP lightweight open section car (probably a 6-6-4), two-tone green NP cars, and other lightweight UP sleepers.
A great treat, when I was in southeast Florida, was to catch either the "City of Miami" or the "South Wind", both of which carried dome cars (the South Wind used an NP sleeper-dome, while the "City" carried a coach dome). They also both tended to have Western sleepers mixed into their consists, making for quite a colorful show.
But for the Seaboard, it was always silver and nothing but.
Randy Resor, aka "NellieBly" passed away on November 1, 2013. We honor his memory and his devotion to railroading at railroad.net.