4959 remains as the color code for DuPont only the last letter changes for quality.
4959A is for Centari.

Call 1-800-338-7668 option 3 option 1 for DuPonts Color Library. They will give you a closest match. Then do a spray out to verify. Colors varied from plant to plant and year to year. So check before you get too far.

Geno