Concerning the early and late Race Hemi Orange, I have not seen any significant color difference between samples of original paint parts from 64-68, I can only assume that the "Late" versions were just variables in either the paint samples matched to or a variable in the samples themselves, I HIGHLY doubt it was a special color formula. Frank sells two versions, IMO based on my original; paint parts samples the early version is the best match for any year that used Race Hemi Orange.