Hope this gathering helps...some of the links may be broken, tsk.
The many sensei have repeatedly stated that the Hairyokushoku (gray-green) is the Zero color. These men are those who worked with the various Japanese paint releases of that color...thus I only repeat my teachers.
Having seen J3 (made of black and white) on the lower surface of the N1K1 I worked on in 1975, I was seeing what I expected to see on the Zero (with my meager 1975 era knowledge). When I viewed the samples of the Zero and RUFE...I was taken aback by the gray-GREEN of the rubbed samples (to get rid of any residual chalking). My sensei began to assure the facts.
Here is a gathering of data which might help open your eyes...some of which is 'old hat' yet there should be new stuff:
The corrosion control effort by IJN was to apply a zinc chromate style prevention on the interior of the exterior skin...called "Aotake", it is translated as "blue bamboo". It is also spelled "Aodake" when it is used in select Japanese sentences...yet the non-Japanese use "Aotake" as the general term. However, the modeler must know WHICH "Aotake" is used by which manufacturer...as there are TWO VERSIONS: one is a "candy blue" as the name suggests, and the other is a "candy green". "candy" colors refer to those paints we once used on car models...but in this case the application over a "silver" metal paint gives a most satisfactory solution.
LOADS of arguments came from select American students when the Japanese sensei told of "Light Bronzing Lacquer #49, type 2". The common name is "Ameiro" ("Ame" means candy brown, amber, etc; and "iro" means color). This clear coat had been applied to propellers of Japanese and American navy aircraft. It was TRIED on the production line of the entire A5M airframe and the coating FAILED. It was NOT USED after 1940....even removed from IJN propellers.
We continue to relate the history to each other about what the Japanese sensei tell us... rather than the rumors of purple RUFEs, and yellow or brown Zeros. What follows are bits which the Japanese continue to repeat...!
Mitsubishi built A6M landing gear covers and wheel wells are the undersurface color.
Nakajima built Zero landing gear gear leg painted with the undersurface color on both sides, the well itself and interior of the small crescent shaped door was in aotake.
Below is described that M0/M1 gray-green color in more detail. This newly publicized color has problems in that it chalks on wrecks sitting in the sun... and even in combat as shown on the Zeros in China and in the Philippines:
Note the scans of the same A6M3 model 22 lower surface from a Rabaul crash and sent to me prior to its sale to a Japanese sensei. I took the scans outside at 1030 hours and indoor under tungsten light.
My personal interest is "Pearl Harbor" and those Japanese operation details which has been a study for over fifty years. Any of THOSE questions are easily answered at: http://japanese-aviation.forumeiros.com/f2-color-profiles
> others are addressed at:http://www.pearlharbor-history.org/
The following gatherings were made over several 'sessions' with my various Japanese sensei as an addition after our publication of "Shinjuwan no 101 Ki (Pearl Harbor & 101 Aircraft)", REPLICA magazine, Jan 1990.
Hope this may help widen your eyes in the Zero, VAL or KATE ...or even the RUFE modeling efforts:
The interior of the Zero's exterior skin was a BLUE aotake (KATE and VAL was green aotake) used to determine what was protected and contrasts quite well with the interior green used for the components. See the attached model's interior and a real Zero's instrument board (use Tamiya XF-71 cockpit interior). Uniquely, we once thought that thick aotake coats had a green color...or that it turned green (how did we know it turned green unless we had painted it originally!). We now know that select manufacturers used a green and others used blue. Simple...use a base aluminum then overcoat with a clear "candy" blue or green.
Mitsubishi used a blue-black paint for both the exterior and interior of cowlings and the fuselage deck underneath the cockpit. Actually any 7 to 3 mix of black and dark blue paints will give you a good result. Nakajima used a true black colour. "Most important thing we have to remember is that the color was controlled by military standards. Therefore, there should not have been differences among color of each airplane manufacturers. Of course, even so, regional factor caused some difference. Mitsubishi was located in Western part of Japan and Nakajima was located in Eastern part of Japan. So, Mitsubishi used colors manufactured in Western area and Nakajima bought the color from companies located in Eastern region. Even today, it is almost impossible to produce 100% same color in different timing and location. Black on cowling is an example of this. After 1943, all material was controlled by a ministry. This means that ministry decided all allocation of material. After this happened, talking about color difference has less meaning."
Mitsubishi-built Zeros had their wheel wells painted in the gloss gray-green color as the underside; the Nakajima-built Zeros had the wheel wells finished in the bluish preservative paint. Landing gear struts are black. No Nakajima built Zeros were constructed in time to be at Pearl Harbor.
Of further interest, the black dangling aileron balances were a quick fix for limited combat ability. This was to keep the planes from having high speed crashes and skin ripple during dives. These "Pearl Harbor" vintage Zeros were flight restricted, until an internal fix was done on the Mitsubishi production line. [had we only known! tsk] This was not used by Nakajima as the internal fix was made early enough for their production line.
For the Jan 1990 REPLICA mag article "Shinjuwan no 101 ki", H. Yoshimura, M. Asano and I found that the stripes on the CV aircraft at Pearl Harbor did NOT go under the fuselage...at least for those we found photos.
We also found that the stripe on DI-108 on Akutan Island DID wrap under the fuselage. So we became wary.
For those Tainan Kokutai aircraft we have found that the diagonal stripe did NOT go under the fuselage.
Why did the majority NOT go under the fuselage was a puzzle?
THEN I was involved with the Confederate Air Force Zero 21....and heard the many complaints by the dude who painted the complete wrap of the fuselage stripes on EII-102, leading me to understand why the fuselage stripes did NOT go under the fuselage. There just was no room when on your back painting the stripe!
OH, the entire restoration crew each signed our names on that rear most stripe far under the fuselage, which was there until the Pacific Air Museum got their hands on this plane!
The REAR of the propeller is an aged chocolate bar brown in the attached scan...NOT black. Yet it IS black. I was not completely 'sold' on chocolate but the Japanese owner of this blade assures it is black.
It would have been dumb, as some suggest, for the Japanese to use only lap belts...on the Zero....they HAD to use a shoulder belt. I don't have the width measurement yet it had many grommets for the belt buckle. The shoulder belt came across the left shoulder as seen in the attached blue print and illustration. The connections to hard points within the cockpit is poorly defined. Japanese sensei H. Sugiyama added more about the seat and the Type 97 Zabuton/parachute seat pack with the attached published illustration.
The latest color discoverys are from Japan. Several Japanese researchers made a concerted task to locate color documents with great success. Three Japanese Navy documents and a IJA document have been located thus far.
The first document published was Feb 1942 IJN Document Number '0266', a test of variety of colors applied to the famous Zero. A large amount of discussion began, yet the conclusion was that more searching was required.
The next document located and GAKKEN magazine printed was an April 1945 IJN document number '8609' and the number system was drastically different than '0266' for the same color name.
Digging continued. and TWO copies of the November 1938 IJN document [April 1942 revision] “Temporary Specification No.117 Additional Volume” were located. This truely laid out the colors used in WWII (see attached 'spread' of the swatches) and the other documents (above) helped to show some changes as the war progressed.http://www5d.biglobe.ne.jp/~cocoro/subw117-2.htm
The Japanese researchers confirm that the color, used on the Zero prototype thru the A6M3 model 22 ...and Mitsubishi built A6M5, is called 'Hairyokushoku' (literally gray-green)...including the RUFE [attached are samples of gloss 'Hairyokushoku' from the crash of Zero 21 at Kaneohe NAS, Oahu -Lt Fusata Iida- and from a RUFE at Tulagi. The RUFE had been submerged for six months before recovery.] That color 'M0/M1...Hairyokushoku' may be seen in the 'M' series of the '117' color swatches. Some modelers have suggested that this gray-GREEN is nearly like RLM 02/RLM63/Gruengrau, I do not know. Tamiya Plastic Model Company in Japan has produced this color -lightened- for use on 1/32 and 1/48 miniatures (note attached swatch).
Uniquely, in October 1941, the orders came down for VALs and KATEs of the Kido Butai to received camouflage. At that moment, these VALs and KATEs were in NMF, with silver painted on the fabric surfaces. Most had red lacquer tails.
Japanese witnesses recall that this painting had to be worked around the training schedule. KATE and VAL types were training at various airfields. Paint stocks at each of the bases were used to paint both Nakajima aircraft and Aichi aircraft.
Most fields had only gray-green paint in enough quanity, then those aircraft got gray-green...while a few fields had only gloss 'Tsuchi' (earth, mud) 'iro' (color) called 'I3'. Thus you may understand there was little uniformity between aircraft carriers. Of interest, R. Watanabe (in his cited article) asssured that this "I3" was used for a short while as a undercoat on Nakajima A6M2 and A6M2-N with the gray-green as final coat.
As we see from relics, the Akagi and Kaga VALs and KATEs received FIELD APPLICATIONS of greenish-gray on their undersurface. Akagi/Kaga KATEs were at Kagoshima Field. Akagi/Kaga VALs were at Tomitaka Field.
Soryu/Hiryu were at Kasanohara Field and received the khaki I3. They stretched their stock of the semi-gloss D2 dark green by application of thinner coats to the KATEs than what other units' aircraft received.
The Shokaku KATEs were at Usa Field and received I3:
Zuikaku KATEs were there, too.
Other training fields were:
Izumi Field: Soryu/Hiryu KATEs
Oita Field: Shokaku/Zuikaku VALs
Zeros were already in a factory finish 'M0/M1'. They trained at:
Omura Field; Oita Field; and Saeki Field.
Thus from relics, photos, and witnesses:
Akagi VALs and KATEs were painted in 'hairyokushoku' [translated 'gray-green', greenish gray]...the KATEs were then painted over the upper surfaces with dark green. The upper surface dark green 'D2' color may be seen in the 'D' series of the '117' color swatches.
An UN-weathered sample, recovered by a USS Raleigh crewman from the Akagi dive bomber crash on USS Curtiss, is also colored gray-green.
Kaga VALs and Kaga KATEs were coated gray-green and were then the KATEs were covered over the upper surfaces with dark green; the Kaga KATEs' red tails was over coated with a brown to probably aid in reforming.
Soryu and Hiryu KATEs were coated with I3, a tannish, brownish khaki color [which American witnesses at crash sites at Pearl Harbor called 'mustard']. This is quite compatable to Luftwaffe RLM 79 SANDBRAUN. The KATEs then had a thin coating of green was applied to the upper surface. The witness reports say that brown flakes were showing on these KATEs. A photo of Juzo Mori standing nexxt to his B5N in early 1942 shows the I3 showing through the D2 green and newly applied paint repairs to the chipped paint using more I3.
Shokaku and Zuikaku VALs received the I3 coating...
We know that Shokaku KATEs got the I3 coating, did the Zuikaku KATEs? The Shokaku KATEs only got a dark green application over the upper surface of the main wings and horizontal stabs...and the dorsal spine of the fuselage... While the Zuikaku KATEs got green over all the upper surface [like Akagi].
Sidnei Maneta has nice artwork for 'Pearl Harbor' and other CV borne actions:
Tamiya produced this 灰緑色 'Hairyokushoku' [literally 'gray-green'] for their 1/32 Zero 21 and 'unsaturated' (lightened) the color for use on 1/32 and 1/48 scale miniatures:
Sweet has 'unsaturated' the 灰緑色 'Hairyokushoku' color even further for 1/144 scale Zeros.
Gaia has their 灰緑色 'Hairyokushoku' version:
and Mr Color is selling C-128 灰緑色 'Hairyokushoku', too.
Within the above are bits about the A6M5 series. More is to come...yea! The term "Olive gray" used by some US researchers is the Japanese "gray green" cited above. This color was used by BOTH Mitsubishi and Nakajima from the beginning of production thru to the end of the war with one exception found thus far...the Nakajima A6M5...which has "J3" Hai (gray) iro (color) undersurface.