A couple of notes: First on the rear markers red, on an engine running light (no cars or caboose) which is defined as a train in the PRR and other rule books, a red marker must be shown to the rear.
Second, by the time freight diesels were very common, ie when the trainmasters were delivered, all the lettering was "buff" which is basically a yellow. Gold was used a little on the early passenger diesels but I think that practice ended fairly quickly and by the 50s even the passenger steamers were getting buff lettering.
Finally al first generation pennsy diesels with the exception of the RSD 7 and RSD 15, were set up as long hood forward. Second generation started with the low nose alcos, GEs, and EMDs such as the GP30.
