AR-323 had many names between 1965 and 1980: Farina Blue, Skipper Blue, Preussian Blue, Prussian Blue, Medium Blue. The Ditzler code is 12584 and the DuPont code is 37004.
Thanks to this thead, I learned that I put the wrong AR code in the
1972 Color Reference Chart. I listed AR-363 instead of AR-323 (possibly a typo) which is a blue that was available from 1981 to 1984.