Continuing a Goshikisen (Type 5 Fighter) theme this brief exploration begins with the University of Illinois example photographed in colour by Charles 'Chuck' J Graham in 1949 when he was in his third year at the University and attributed by both Chuck Graham and Jim Long with c/n 13012, manufactured by Kawasaki in July 1945 (at the Miyakonojo plant on Kyushu according to Jim Long, but at Kagamigahara's Ichinomiya dispersal plant according to Joe Picarella). The aircraft was one of four former 111th Sentai examples found at Komaki airfield and taken to the USA. It was allocated the 'Foreign Equipment' identifying code FE-314 (listed in March 1946 as FE-N314) and subsequently the 'Foreign Technology' code T2-314. It was on display at the Urbana airfield of the University of Illinois, Champaign, from August 1946 until 1959 when it was sadly scrapped as being beyond repair. Copies of Chuck Graham's colour photographs were provided to the late Al Makiel, Don Thorpe, Bill Thompson and Toda-san, the editor of Koku-Fan magazine. Some of the photos were reproduced uncredited in one of the Bunrin-do published Famous Aircraft of the World (FAOW) editions on the Ki-100, No.36 of 1973 (see heading image). The photos from the Al Makiel collection were subsequently provided to the late Jim Lansdale.
The first four colour chips shown above are rendered from Munsell comparisons of the exterior and interior paint provided to Jim Lansdale by Chuck Graham and shared with this author in 2008. Leaving aside for the moment the provenance of the paint finish (see below) they are indicative of the variegated and 'chalked' paint surface of a weathered aircraft standing exposed for four years. The lightest hue is similar to an FS 595 value attributed to the early Zero colour! The colour chip shown below is rendered from the Munsell value from a colorimeter measured sample of the aircraft's skin provided to Jim Lansdale by Chuck Graham. Note that Munsell 7.5 Y 4/2 is the same colour value as Thorpe's A2 Olive Green.
Opinions have differed as to whether the paint finish of this aircraft was original, either in whole or in part, or was the result of re-painting after capture. The airframe displayed a number of anomalies, not least a grey painted finish on the under surfaces not typical for the Ki-100 and similar in hue to the US Neutral Gray colour. The rear fuselage trestle location stencil appears to have been masked off to reveal a darker, greener finish but the wing stencils show no such evidence. The paint exposed by removal of the tail fairing also appears slightly darker, as would be expected of a protected paint surface. The yellow wing leading edge IFF strips were painted over in the airframe colour, leaving only 'stars' around the gun apertures. On the other hand the patches of bare metal from an unprimed finish reveal no clues as to the existence of a previous paint layer. Al Makiel was of the opinion that the aircraft had been re-painted with US Olive Drab as the University had plans to restore the aircraft as part of a plan to establish an aircraft museum - which was not achieved. In 2008 Chuck Graham opined differently that there were no signs that the University had re-painted the aircraft and the finish appeared original, although he thought that it was possible it had been re-painted when in US hands before that. The Aero Detail 32 book on the Ki-100 by Joe Picarella ((Kaiga/Modelkasten 2009) asserts that the aircraft was re-painted in US colours and in October 2005 this belief had been affirmed by him to the author with the observation that the fuselage hinomaru had been applied over an overpainted star and bar shape as well as noting the apparently masked off trestle stencil and overpainted fuel pressure regulator cover (originally red). He also noted the unreliability of colours as displayed in photos and that was reinforced by Chuck Graham who observed that the actual appearance of the colour was more 'greenish' than the photos suggest. It is possible that the aircraft had been only partially re-painted as the US Olive Drab and the Japanese Army Air Force's # 7 Ohryoku nana go shoku (yellow green) colour are similar, both having their origin in the PC10 'Khaki Drab' (an olive brown hue) of the Royal Flying Corps. The green vs brown paradox is endemic to the individually subjective viewing and assessing of this colour space.
The colour chip above is rendered from the Munsell value attributed by Joe Picarella and Helen Maiden to the original exterior and interior paint colour of Ki-100 c/n 16336, the surviving and restored example at the RAF Museum, which was manufactured at the Kawasaki Kagamigahara plant in June 1945. In Japanese Aircraft Interiors by Robert C Mikesh (Monogram Aviation Publications 2000) it is stated that "This color is believed to to be the Kawasaki standard factory-green of the late 1944-45 period, used both structurally and externally." The colour chip in the Aero Detail book is described simply as 'green' but the Japanese characters used are 暗緑色 (Anryoku shoku - dark green colour). The slightly more olive green finish of this example, still close to the # 7 colour standard, is consistent with information from a Japanese researcher 'Maru' that the Ki-100s were delivered in batches of varying colour, with an early batch finished in the # 7 olive brown colour sent to the 18th Sentai and a later batch in a 'dark green' finish sent to the 5th Sentai. It appears that some late production Ki-45s were also solidly finished in this olive green colour on their upper surfaces, which is slightly more greenish than FS 33070 (@3.38). Bear in mind that FS 34083 is a very close equivalent to the wartime RAF Dark Green colour standard (@ 1.14).
The colour chip above is rendered from the Munsell value attributed by Katsushi Owaki to a Ki-100 artifact at the Kisarazu JGSDF (陸上自衛隊 Rikujō Jieitai) museum and attributed to the aircraft flown by Sgt Maj Yasuo Takeshi. The dark black(ish) brown colour is associated with both the Ki-100 and as an overall finish on some Ki-45s, attributed by several Japanese sources as a night fighting camouflage sometimes referred to as 'yokan iro' (羊羹色) from a type of Japanese sweet delicacy (the Ki-100 was also flown in night combat). This colour has been misleadingly referred to as 'charcoal' in some English language sources, resulting in illustrations of 'black' Ki-100s, whereas the Japanese colour name is Kuro Kasshoku (黒褐色 - black brown colour). At first believed to be an expedient variant of the # 7 colour (still possible - PC10 also showed this variance depending on the percentage of ferric content in the iron oxide pigment used) it also bears a strong resemblance to the IJAAF colour standard # 43 Tochi or Tsuchi iro (土地色 - earth or soil colour), the intended use of which is uncertain. However # 43 must have been of some importance to the IJAAF as it was carried forward in the February 1945 reconciliation of paint colours as standard 2-2 with no IJN equivalents.
Therefore there appear to be at least three colour variations in which Ki-100 models can legitimately be finished, although attributing them to specific aircraft and units is more difficult: - the # 7 olive brown (olive drab) colour with all its variegation and weathering characteristics; a slightly more olive green (which could be approximately represented by the so-called 'Kawasaki Green' available in many hobby paint ranges); and the black(ish) brown colour which is similar to, but not quite as reddish and slightly more greyish than, the Luftwaffe RLM 81 Braunviolett colour (as measured from the 1941 Tafel 5). AK Interactive Real Colors RC323 RLM 81 is similar, whilst the Gunze H-421 RLM 81 is a little greener.
This blog should be viewed as an updated revision to any previous Ki-100 colour discussions here and has been prepared in acknowledgement and with much gratitude for the input and valued data of Ken Glass, Chuck Graham, the late Jim Lansdale, Jim Long, Katsushi Owaki and Joe Picarella, as well as kind assistance with translation from Tetsuya Inoue.
Image credit: Heading photo © 1949 Charles J Graham via M Toda scanned from FAOW # 36 of April 1973 & reproduced for academic discussion; All rendered colour chips © 2019 Aviation of Japan