The Dupont code of Niagara Blue Dark is: BS048, PPG is: 439. I think you mean Duchess Blue as I don't think there is a Duchess Grey. Duchess Blue Dupont is: GS733 and PPG is: 123. You might want to purchase a Model A Ford Paint & Finish Guide. It has a lot of good information in, like the paint codes, where the different colors belong and all the paint color chips.
What are the paint codes for lite and dark Niagra blue and the reveals ,Duchess grey?