Dupont does not seem to come up with modern codes as easily as does PPG. Also, PPG provided the same code for Mariner Blue from 47-55; however, the name was the same from 47-55, but the code changed in 1953. PPG had different codes for pre-53 and 53-55.
There is information about how to contact PPG for modern codes
at the bottom of this Tech-Tip. 
