John,
Chevrolet documents do not list Brewster Green as a factory option color for 1954 trucks or Sedan Delivery.
The "standard" color in 1954 was Juniper Green (DuPont Dulux 93-72001) and it is the closest 1954 green (In apprearance) to Brewster Green. Look at Ralphy's posting in this forum (1951-1954 Truck Colors Plus).
I have found PPG to be better in having "recipes" for older colors.
Tim
