Please, could anyone tell me what is the color code of Tamiya and Humbrol of dark brown that had japanese ground army aircraft towards the end of WWII?.
Regards,
Pacopepe
Try this site
http://www.ipmsstockholm.org/colorcharts/colorcharts.asp
Gondor
Another very competent source for Japanese WWII aircraft colors is the Arawasi Flying Eagle blog.
http://arawasi-wildeagles.blogspot.de/
There are articles covering the various color shades, and you might also directly ask for help.
Nick Millman's site is also a good resource:
http://www.aviationofjapan.com
First note that the late war brown was actually a green-brown similar to olive drab. ;D
IJAAF #7 (Olive brown variously called "late war brown", "Home Defence khaki", "khaki black", "deep green brown")
http://www.aviationofjapan.com/2011/03/more-about-jaaf-7-ohryoku-nana-go-shoku.html
The colour varied in appearance in a range of green to brown for a number of reasons and can be said in some cases to be similar to FS 33070 Olive Drab.
A mix of GSI Creos (Gunze) (Aqeous Hobby Color)H78 Olive Drab 2 and H405 Olive Green is used on this Ki-61-II Kai:
http://www.aviationofjapan.com/2013/12/vojta-halamiceks-ki-61-ii-kai-bubbletop.html
The iModelkit app gives rough equivalencies as follows:
H78 (Tamiya XF62 or Humbrol 66)
H405 (Tamiya XF81, Humbrol 252)
FS 33070 (No Tamiya, Humbrol 75)
Perhaps the best example of the elusiveness of the colour is in this Ki-61-II build:
http://www.aviationofjapan.com/2012/09/another-ki-61-ii-kai-bubbletop.html
"It's probably too much to hope that those who argue interminably about the paint colours shown in wartime colour photos will take note of (and on board) the very different hues seen on the same model in the images here even though the red of the Hinomaru (or other chosen "control" colour) appears similar in each. "
(In some photos the model appears green, in others brown)
So in short, pick an olive brown/olive drab that suits you and paint away. ;D
Besides, NEVER trust a picture you see in print or in the WWW, esp. when these are based on old photographs. The material might have suffered from age and other influences, and the transfer to another medium always comes with a change of color, and there's also the effect of weathering or climate and light conditions when the picture was taken.
The pictures replication through print or on a screen will also differ considerably. No model is "realistic" unless you have the real thing side by side, in real life and in good light. Any discussion about "real colors" is IMHO futile - if you get the impression of the object right, it's IMHO fine. After all, it's about a model, which is a simplified representation of a more complex issue. The comment on the Ki-61 adresses the issue well.