An olive drab Bessemer boxcar? A couple items have shown up in this color and there seems to be some dispute about what color this is. Some say the obvious, OD, but others claim this is a faded light brown. I have observed this color car several times and find it to be a result of sun fading.
Below is a comparison photo showing this car alongside a regular brown boxcar.



(Courtesy of Gary Mocko)


Above are pictures of both sides of a 59 UP Stock Car I found. The results of sun fading can be clearly seen. The picture to the left looks pretty much normal while the right picture shows the more faded side. It is interesting that the door did not seem to be as affected as the rest of the car.