I defer to Bryan who may have better info, but....
PC Freight cars were painted "Deepwater Green" - the classic medium green, slightly jadish color associated with PC.
Passenger cars were painted a color the RR called "Hunter Green" - but it was NOT the same Hunter Green used by the NH.
It would best be described as something like a lighter hunter green. There is no commercial paint and I've never really
seen it reproduced as I personally remember it, although the Kato PC cars were close, but too light.
This is very close to what I remember: