OF AMEIRO CLOUD INTO HAI-RYOKUSHOKU SKY
by Yoshihito Kurosu
translation by Ryutaro Nambu
1. KNOWN FACTS
1.1. Birth of Reisen and its Background
In 1937, Mitsubishi started the
development of A6M1 12-shi Kanjo Sentoki (Type 12 Experimental Carrier
Fighter). The 12 corresponds to 1937, the twelfth of Showa era under
Emperor Hirohito's rein.
In that same year, 1937, IJN
imported thirty (or twelve) He-112 fighters from Germany, and gave them a
fighter designation "A7He1". Those He-112s were painted in RLM63 Grungrau.
The first prototype of 12-shi
(pronounced "ju-ni-shi") flew in April 1939, followed by the second
machine in October 1939. The third machine, with a new Sakae engine, was
completed around December 1939 or January 1940. Deviating from IJN's standard
orange color for experimental and prototype aircraft, Mitsubishi painted those
prototype machines in "hai-ryokushoku" (literally ash green,
meaning greenish ash). [see Appendix B: Color Names in Japanese]
In July 1940, IJN
adopted A6M2 officially as Rei-shiki Kanjo Sentoki (Type 0 Carrier
Fighter). The "0" (pronounced "rei") in the designation
means 2600 in the Japanese Imperial era, which translates into 1940AD.
(Similarly, 99 of D3A means 2599 or 1939AD.) Exact translation of "kanjo"
is on-shipboard or embarked.
Before IJN introduced Rei-shiki Kanjo
Sentoki (often dubbed Reisen or rather colloquially Zero-sen),
it used to paint its carrier fighters in silver overall. No gray examples were
known. Apart from carrier fighters, Aichi D3A Type 99 Carrier Dive Bomber (99-kanbaku),
Mitsubishi F1M Type 0 Observation Seaplane (Reikan), and Aichi E13A Type
0 Reconnaissance Seaplane (Reisuitei) were possibly painted in "mei-kaishoku"
(light ash, IJA notation "J1". Some people call that color "mei-kai-hakushoku"
or "mei-hai-hakushoku" (literally light ash white, meaning
light whitish ash).
No IJN documents known today state that
protective clear topcoat was applied to Zeros or to any other navy fighters.
Among the existing photos of Mitsubishi A5M Type 96 Carrier Fighter (96-kansen),
a few machines seem to have somewhat darker shade than the ordinary silver
finish. Some researchers speculate that the darker look was from a possible
application of tinted topcoat. It may as well be attributed, however, to
photographic conditions such as light, exposure, film characteristics, use of
filter, and development process. IJN veterans remarked, as I overheard from a
reliable researcher, that they had seen Type 96s with a field-applied protective
topcoat of slightly tinted varnish (or dope?). But there is no evidence
whatsoever that Zero received a similar topcoat.
1.2. Kugiho No. 0266
(short for Koku Gijutsu Sho or Air Engineering Arsenal) carried out a
series of camouflage test at Yoko-ku (short for Yokosuka Kaigun
Kokutai or Yokosuka Navy Air Group) between November 1941 and
February 1942. Kugisho summarized the test results in "Kugiho"[Air
Engineering Report] No. 0266: Research on Camouflage for Type 0 Carrier Fighter
(Research on Aircraft Color Schemes)". The 0266 was navy's classified
document, of which perhaps less than a hundred copies should have existed. A
copy, known to be the only one existing today, is in a private collection and
In the 0266, two grays, J2 ("sei-kaishoku"
or bluish ash) and J3 ("haiiro" or ash), were
reported, together with greens. Sample color chips were attached to the 0266
copy, but their tones have not been confirmed by matching to FS, Munsell, or
Methuen chips, as the current owner does not disclose them. J1 was not tested in
the 0266, and no color chip was attached. IJN's standard colors, including J1,
J2, and J3, were originally glossy. Additives were used to give the colors matte
finish in the tests.
In search of an effective camouflage
scheme, the Kugisho team compared the experimental colors against the
standard Zero scheme. The reporter of the 0266 wrote about the standard Zero
color as follows:
"The color of
gen-yo Type 0 Carrier Fighters is similar to a J3 (haiiro) slightly tinted with
ameiro, but differs from the experimental colors as it has luster."
in Japanese literally means candy-color or caramel-color, but is commonly used
to mean transparent yellowish brown, brown, or light brown, such as honey, maple
syrup, and amber. "Gen-yo" translates to "currently in
service" or "now in use".
In other parts of the report, the 0266
reporter temporarily called that gen-yo color as "ameiro"
or "gen-yo ameiro" for brevity. The report consists of lists
and short comments, where nonce words like them may have served well for
conciseness. Such use of the word "ameiro" was only temporary
and exceptional by the 0266 reporter alone, and no other official IJN documents
known today use such expressions, not even a single mention.
1.3. J3 and two-color
J3 was called "haiiro"
(ash) in the 0266. But As I heard directly from two reliable researchers who had
seen the existing 0266 color chips, J3 was like RLM63. One of them remarked:
"J3 was close to RLM63 in hue, but much lighter than RLM63."
The 0266 concluded from test results that
"no-ryoku-kokushoku" (deep greenish black) as an upper surface
color had a good camouflage effect from its low visibility.
In July 1943, IJN HQ issued a directive
specifying a two-color camouflage scheme. Field application preceded the
directive; units on the tropical fronts began practicing a top-side green
camouflage since around the summer of 1942.
The colors of the two-color scheme were not
strictly kept to the norm. Nakajima's colors were different from Mitsubishi's
colors. And the colors may also have varied over time. For instance,
Mitsubishi's later color for top-side was a very deep shade of dark green, much
darker than its earlier color. Similarly, the lower surface color ranged from haiiro
"Hiko-ki Keikaku You-ryou-sho Kaitei-an" (Proposal for the
revisions of aircraft planning procedures) issued by Navy Air Command HQ in
March 1944 has a table of standard colors and codes under "Kari-kikaku
117 Shiki-betsu Hyojun" (Provisional Standard 117 Color Norms). The
table specified the upper-surface color as D1 "an-ryokushoku"
(dark green) and the lower-surface color as J3 "hai-ryokushoku"
(greenish ash). Notice that J3's notation was different from the 0266, in which
it had been called "haiiro". (I will touch on this difference
in Section 3.1.)
The A6M5 Zero Model 52 on display in the
Smithsonian National Air and Space Museum, famous for its strict and precise
researches and restoration, is painted in dark green similar to Munsell 10G3/2
on upper surfaces and in light gray similar to Munsell N7.5 on lower surfaces.
That particular machine was captured on Saipan Island in April 1944, was sent to
the U.S., and underwent an evaluation program with all of its markings and
colors stripped for complete inspection. The Museum restored the machine to what
a Zero at Saipan should have looked like in early 1944. Although the machine was
actually made by Mitsubishi, the Museum painted it in Nakajima color version.
The tailcode too was of one of Nakajima-made machines. More information on this
machine is available at the Institute's WebPages at: http://www.nasm.edu/nasm/AERO/AIRCRAFT/a6m5zero.htm
1.4. Examinations of relics
Mr. James F. Lansdale made an extensive
study of existing Zero relics that he and other researchers matched against
FS595b color chips. Mr. Lansdale reports that some samples with weathered or
faded surface showed chalky pale gray close to FS36357, FS36492, or FS36495.
When the samples were "lightly buffed", as he explains, many of them
revealed olive-gray colors (beneath the weathered surfaces) close to FS16350,
FS24201, or Munsell 7.8Y5.5/2.5.
2. PERSONAL ACCOUNTS
In his book "Reisen",
Jiro Horikoshi, Mitsubishi's chief designer of Zero, recalled: "12-shi
was painted in dimly-shining hai-ryokushoku except black engine
The famous ace pilot
Saburo Sakai, who flew Zeros since his early days at 12-ku (short for
"Dai 12 Kaigun Kokutai" or 12th Navy Air Group), writes in some
of his books that Zero's color was "mei-kaishoku" or light ash.
He also writes about his first impression of Zero in his 1992 book "Zerosen
no Shinjitsu [The Truth of Zero]" as follows:
"Till then, IJN warplanes always
sported brilliant silver overall with bright-red hinomaru. As Zero was
introduced, the color scheme changed to haiiro. Zero looked something like
aircraft borrowed from some foreign country. In contrast to 96-kansen's sharp
and sturdy appearance like a keen-edged sword, Zero looked sleek, smooth, and
Mr. Sakai has a light bluish ash sample
that corroborates his memories. His sample was taken from the relics of his
plane recovered in 1994 from the clear-water swamp near Henderson airfield in
In his book "Koga's
Zero", Jim Rearden quoted Lieut. Comdr. Eddie R. Sanders, a U.S. Navy
pilot who tested the Zero captured at Akutan Island of Aleutian Islands, as
reporting: "The original finish was a very smooth light gray, tinted with
blue light green." (I think this report quite credible, for it covers
technical details of a relatively new machine in its condition soon after the
I had a chance to talk
with a senior modeler, who used to work for Kugisho when he was young.
His model of Zero was painted in light greenish ash. He asserted: "As far
as I have seen, the early standard color of Reisen is nothing but THIS
color. I have never seen a brownish or mei-kaishoku variant. This color
was unique to Reisen, and not used for 97-kanko [B5N] or 99-kanbaku
3.1. J3 versus the
To describe J3, Provisional
Standard 117 used the notation "hai-ryokushoku" rather than
"haiiro". I think 117's notation is more precise and indicative
than 0266's notation about the actual tone of J3. It is not
inconsistent that J3 actually had a greenish tint and that the 0266
reporter described such color as haiiro; hai-ryokushoku is part of
colors broadly categorized as haiiro. Conversely, if J3 had had no green
content, then the 117 should have not called it hai-ryokushoku. As the
two researchers confirmed, J3 was not a plane gray but a gray with a greenish
Then what about the color of gen-yo
Zeros? As I judge from the known facts, it was not a paint batch variation
within the J3 specs, but what you may call it "Zero special", a
separate color expressly prescribed by Mitsubishi for Zero. (I coined the name
"Zero special", which I think is better than the misleading "ameiro".
I will explain more on this issue later in Section 3.5.)
No matter what you name it, the gen-yo color was a glossy light greenish
ash (hai-ryokushoku) slightly brownish or yellow-brownish than the J3 of
0266 sample chip.
It is incorrect to reason that gen-yo
Zeros were painted in J1, or that J1 was "ameiro". If J1 had
been the standard Zero color, the 0266 reporter should have remarked as such. He
should have simply written "The color of gen-yo Type 0 Carrier
Fighters is J1, similar to J3 but slightly tinted with ameiro...".
Likewise, if J1 had been commonly called "ameiro" then he
should have written "The color of gen-yo Type 0 Carrier Fighters is
similar to a J3 (haiiro) slightly tinted with J1 (ameiro)...".
He did neither. That suggests the gen-yo color was not J1; J1 was not ameiro;
and of course, gen-yo color was not ameiro either. Then what could
J1 have looked like? I am almost sure that J1 was a plain light gray (mei-kaishoku).
A researcher whom I trust said so, and I accept his remark as reasonable.
3.2. Paint aging
Both vehicle and pigments of paint age over
years. The vehicle, clear and uncolored when fresh, becomes dull, darkish,
brownish, or yellowish. Pigments of some colors are stable, some are fragile,
and the speed and the extent of aging vary with colors. Weathered and exposed to
sunlight, paint loses its luster in short time, and its surface often becomes
chalky. Acid and other chemical substances contained in air, rain, and soil also
affect painted surfaces.
I sincerely respect Mr. Lansdale's
systematic approach and the hard facts he confirmed. His study gave me a solid
ground to build my interpretation on. The relics suggest what the original
colors might have looked like.
The relics presumably had been exposed to
sunlight and rain or in contact with soil over many years before their recovery.
If we "sand" or scrape the weathered surface, instead of just lightly
buffing it, the inner layer may reveal a color closer to the original condition.
Besides, the inner layer may as well have gone through aging. When assessing
original colors from the existing relics, it is always essential to compensate
for the aging effect of paint, vehicle in particular. I suppose that the color
of the relics looked different from FS16350 or FS24201 in their original,
factory-fresh conditions some fifty years back.
3.3. Influence of imported He-112
What made Mitsubishi drop standard orange
in favor of hai-ryokushoku for its Zero prototypes? IJN's tests of the
imported He-112s coincided with the development of 12-shi.
I speculate that Heinkel's RLM63 Grungrau could possibly have influenced
Mitsubishi over the color scheme of 12-shi.
My arguments on the possible range of
Zero's early overall color boil down to the following three points. First, it
was glossy without any clear topcoat, and close to J3 hai-ryokushoku
slightly tinted with ameiro. Second, it was not FS16350 itself, but
FS16350 less aging effect. Third, it was close to, but not as dark as, RLM63 Grungrau.
In conclusion, I believe the Zero's early
overall color should have been a glossy hai-ryokushoku (light greenish
ash) not as dark as FS16350 or RLM63. And that color, "Zero special"
as I would call it, was different from J1, a plain light gray, and slightly
different from J3, which would later become IJN's standard under-surface color.
I further assess that the tone of J3 as the
under-surface color varied, including less greenish and more bluish tones, and
that mei-kaishoku (light ash) was sometimes field-applied over the
original color on repairs and retouches.
A Japanese illustrator once highlighted the
0266's remark that the color of gen-yo Zero was like
"a J3 (gray) slightly tinted with ameiro" and generalized it,
without any factual grounds, into an assertion that IJN fighters had usually
received a protective topcoat of clear ameiro. Over time, he has toned
down his words, became shy to call it "ameiro", and eventually
changed the expression to "ryoku-kasshoku (ameiro)".
("Ryoku-kasshoku" means greenish brown in Japanese.)
Shortening "mei-kaishoku tinted
with ryoku-kasshoku" (light ash tinted with greenish brown) into
just ryoku-kasshoku" is as incorrect and misleading as calling
"hai-iro slightly tinted with ameiro" an "ameiro".
It is just like calling a gull gray slightly tinted with blue as a mere
"blue", or shortening duck egg green to a "duck".
The notation "ryoku-kasshoku (ameiro)"
is also improper, as it gives a totally wrong impression that ryoku-kasshoku
(greenish brown) is equivalent to ameiro.
Those misuses of words led to
misconceptions by researchers and modelers. Quotations and references further
compounded the confusions so that even some model makers and paint makers
incorrectly cited "ameiro" as IJN's standard color. What a
was painted in hai-ryokushoku, not ameiro. This is the reality.
Appendix A: COLOR OF ZERO TRAINERS
Since 1984, a Japanese researcher has
repeatedly explained and illustrated in many books and magazines that Zero
trainers had been painted in mei-kaishoku or "ameiro".
Without checking with primary sources, some model aircraft writers regarded his
assertion as a matter of course, and painted their Zero trainers as such. Not
very few people have been brainwashed into believing Zero trainers had actually
been painted in mei-kaishoku.
In reality, however, IJN had a principle to
paint training and experimental aircraft in "tou-ou-shoku"
(literally orange yellow but practically orange or mandarin orange; some people
call it "ou-tou-shoku" but tou-ou-shoku is the official
notation). The principle was set out in Air HQ directive #8777 of 29 December
1938 titled "Renshu-ki Kitai Gaimen Toshoku ni kansuru ken" (Re
Outer Airframe Color for Trainers). The directive was reported as stating
"...paint prescriptions and color samples are distributed as
necessary." The "Riku-kaigun Chuo Kyotei" (Army and Navy
Central Agreement) of 15 September 1942 also stated: "Training and
experimental aircraft should be painted in ou-shoku [literally yellow but
practically orange] wherever conditions permit." The overall orange
principle remained effective until superseded by another directive of 3 July
1943. (Mr. Donald W. Thorpe touched on this July 1943 directive in his book
"Japanese Naval Air Force Camouflage and Markings WWII".) Of
course, no official documents show Zero trainers were painted in mei-kaishoku
or hai-ryokushoku. It is barbarous and ridiculous to describe Zero
trainers were painted in ameiro.
Some may argue that Zero trainers in
B&W photos look similar to Zero fighters in early scheme. But that does not
substantiate they actually wore the same color. Orange may as well look like
light gray in B&W photos, as can be seen in the existing photos of Yokosuka
K5Y Type 93 Intermediate Trainer (93-chu-ren), the biplane commonly
dubbed "Aka-tombo" or red dragonfly.
I interviewed an ex-navy engineer, who had
used to repair and modify aircraft at 1st Navy Aircraft Arsenal of Tsuchiura,
Japan. He asserted: "Type 0 Trainer was painted in tou-oushoku, exactly the
same color as used for Type 93 Aka-tombo, a reddish orange. Later,
however, the topside changed to dark green." And he countered my question
by asking: "Kurosu-san, is there any evidence at all that Zero trainers in
mei-kaishoku ever existed?" Of course, I answered "No".
A friend of mine recently showed his 1/72
orange Zero trainer and 1/48 dark-green/orange Zero trainer at a model
exhibition in Osaka. Among visitors was an old man, who used to fly Zero
fighters at an IJN base in Kyusyu after finishing "Yokaren"
(navy's preparatory pilot training course) in 1944. Pointing at his 1/72 orange
Zero trainer, the old man said: "It reminds me of those days."
The old man recalled: "Aka-tombo,
I mean 93-chu-ren, and rei-rensen (Zero trainer)... they are
trainers and therefore were all painted in this color, as far as I saw
them." My friend asked if he had ever seen a Zero trainer in haiiro
scheme, and the old man replied:
"No, at least in Kyushu, where I
stationed, I have never seen Rensen in haiiro. Well, never seen haiiro ones, but
I saw, near the end of the war at Kanoya base, many machines with green paint
applied over orange. Still then, the under surface was in orange."
Pointing at his 1/48 Rensen in
dark-green and orange scheme, the old man continued: "Yeah, just like this.
I heard that maintenance crew had painted green on them."
Development of Zero trainer began in 1942.
At first, it was temporarily called "17-shi Renshu-yo Sentoki"
or Type 17 Experimental Training Fighter. First prototype rolled out in January
1943, and IJN officially adopted it as A6M2-K Rei-shiki Renshu-yo Sento-ki
Ichi-ichi-gata (Type 0 Training Fighter Model 11) on 17 March 1944. Between
April 1943 and July 1945, 21st Navy Air Arsenal of Nagasaki and Hitachi Aircraft
made 515 units.
When Zero trainer entered service in 1943,
IJN was introducing, with the effect of the July 1943 directive, the two-color
camouflage of topside an-ryokushoku with white-rimmed hinomaru and
under surface hai-ryokushoku. Yellow IFF strips on the leading edges of
inboard wings became standard then. Zero fighter's early scheme, hai-ryokushoku
overall, was already obsolete then.
Early scheme Zero fighters invariably had hinomaru
without white rim on the wings, although Nakajima-built machines wore
white-rimmed hinomaru on the fuselage. (I suppose that aimed at easy
distinction for field maintenance; Nakajima's parts were not fully compatible
with Mitsubishi.) By contrast, Zero trainers, like many other navy trainers,
always wore white-rimmed hinomaru on the wings and fuselage. That was
because, as I suppose, hinomaru had to stand out against the background;
the orange overall color needed the white rim.
trainers were not gray or ameiro; they were orange!
Appendix B: COLOR NAMES
Japanese language uses three sets of
characters: Kanji or Chinese characters imported from ancient China; Hiragana
phonetic letters derived from streamlined Kanji manuscripts; and Katakana
phonetic letters derived from Kanji components. Most Kanji
characters have two ways of pronunciation: Kun-yomi, indigenous Japanese
word assigned to Kanji by its meaning; and On-yomi, adopted
ancient Chinese sound.
Most color names of Kun-yomi date
back to the time before Kanji were imported. Later, Kanji were
assigned to those names according to the colors they meant, and On-yomi
names emerged from those Kanji, chiefly for official and academic uses.
For example, iro
(Kun-yomi) and shoku (On-yomi) both correspond to the Kanji
shown left, and mean "color". Many color names in Japanese have a
suffix iro or shoku, as in hai-iro and mei-kaishoku.
names of flowers, plants, animals, and other natural elements often represent
intermediate colors. For example, mizu-iro means water color, hence light
blue; kitsune-iro means fox color, light brown; tsuchi-iro means
earth color, dull brown; and sakura-iro means cherry color, faint pink of
Japanese cherry blossom.
Another way to express intermediate colors
is by compound names: combination of two elementary colors. For example, a
mixture of ash (hai or kai) and green (midori or ryoku)
is hai-midori-iro or hai-ryoku-shoku.
The list below shows some basic
color-related Kanji images. Each image has a background of corresponding
color and a description formatted as: Kun-yomi / On-yomi (English
translation: practical meaning if different from literal translation)
shiro / haku
kuro/ koku (black)
aka / seki (red)
daidai / tou
ki / ou,
midori / ryoku
ao / sei (blue)
ai / ran (indigo)
murasaki / shi
hai / kai (ash,
nezumi / so
(mouse, rat: gray)...not necessarily darker than hai.
cha / sa (tea:
- / katsu (coarse
hemp: brown)...almost interchangeable with cha; combined with shoku,
katsu-shoku becomes kasshoku in liaison; much deeper than British
(BS4880 / 10B-21) hemp.
The following words describe darkness
(value), and sometimes chroma, of colors:
akarui / mei
kurai / an (dark)
koi / nou
awai / tan
A few exapmles: