That feature of RPO 234 might/might-not have been available in early 1954 (those features are not listed in Truck Date Book), but it was certainly available in Truck Data Books by late 1954 (October). And, the Tech Specs shown above is dated May 1954.
If you didn't want the standard "Juniper Green" body color,
then RPO 234 was used and you picked the body color of your choice.
RPO 234 code, was used for many years,
and was available in early 1954.
Depending on the year, body colors may have changed.
Two examples....
Year 1950 - RPO 234 colors Year 1955 - RPO 234 colors 
