When observing un-restored GM trucks of the 1930-55 era, one will notice the majority of these vehicles were originally dark green. An explanation is simple. Green was their standard color! If you did not specify one of the other approximately eleven non-extra cost colors, your truck would be delivered green.
The standard color of truck had been thought of as green since the late 1920’s on many brands. Though yellow, red, and orange was part of the non-extra cost GM paint options, they were mostly offered by businesses that wished to gain attention or follow their company logos. Individuals usually did not order bright colors.
In the Advance Design years, 1947-55, conservative colors were the norm. The standard dark green was followed mostly by dark blue and black. Even maroon was seen on a limited number of GM trucks.