Don't have very much info on 49 coding but will pass on the little bit I have.
Working from an incomplete list of alphabetic colour names ( all makes ) here's the bit I've been able to ascertain.

Windsor Grey Metallic 1949 GM Dupont paint mix code DUM-724
Wedgewood Green 1949-51 GM mix code DU-735
Seaform Green 1949-50 GM mix code DU-732
New Brunswick Blue 1949 GM mix code DU-740
Midnight Blue 1949-51 GM mix code DU-734
Highway Grey 1948-49 GM mix code DU-733

As you see this list isn't complete and doesn't relate back to data plate paint codes.

thanks for your help, I have searched and found only that the 9 means 1949 an d 09 is the colour

thanks JB

Just a suggestion but if you go to ebay and search 1949 Chevy paint chips there might be a set on auction. If there's a pic you might be able to read the codes.

that's a great site , it has 49 Buick regency blue as 09 , I wonder if you could order a Buick colour on a chevrolet

thank you very much

thank you very much