Thorpe's contention in his letter to PAM News that the Japanese standards had not survived was incorrect but for decades they had been of limited access in Japan and treated rather secretively. Sporadic references to official IJN colour designations in Japanese aviation magazines seem not to have been picked up in the West. In neither his letter to PAM New nor in his books did Thorpe refer to the 8609 standard or directly to the facsimile swatches sent by Mr Toda to US researchers. There is also no mention of the Army's Koukaku 39 or Navy's Kariki 117 colour standards. In fact the Army colours book was published in 1968, before those 8609 swatches were made available in 1975. The Navy colours book followed two years later in 1977. The late Jim Lansdale very kindly sent me a copy of the 8609 swatches as sent and the reverse of the working paper laying them out is endorsed as follows and dated November 1975.
'JAAF - JNAF Colors Source M.Toda (Kokufan) via B Mikesh Stated as "Official Color Standards # 8609. Source in Japan unknown - believed standards for one aircraft mfr only -'
It subsequently transpired that Mr Mikesh refuted being the source of the swatches and Jim came to believe that they might have been sent to Al Makiel who at the time was in correspondence with both Mr Toda and Donald Thorpe. Nevertheless the swatches are correct as to their 8609 designations and each swatch is accompanied by a hand written notation with comparable Munsell values, FS values and, except for 2-6, a Thorpe designation in red. The date these notations were added is unknown. Interestingly the red Thorpe notation adjacent to the 2-6 swatch is 'None'! With the L*a*b" values of the 8609 swatches measured and reported in 2023 it is now possible to present them in direct comparison to the 1975 assessments and the Thorpe colours, with the cautionary understanding that 48 years has passed between them.
Image credit:- Book covers © 1968 & 1977 Aero Publishers, Inc.; Magazine cover & excerpts © 1980 PAM News International published by Independent Magazines Ltd.; Thorpe Table © 2005 William Leyh & Nick Millman; Thorpe Colour Chips pamphlet images via Pat Donahue.