Grey Blue Cockpit Interior in Ki-61

From 1936 the grey-blue paint was to be applied as an overall primer to replace aotake, sometimes with the addition of # 17 Faint Blue colour (Tan Sei shoku - 淡青色)  as a middle coat before the grey green # 1 Ash Green colour (Hai Ryoku shoku - 灰緑色) was applied to external surfaces in top coats, sanded and polished. The whole interior, including the cockpit, was to be painted the grey blue colour and this was introduced with the Ki-15, Ki-21 and Ki-27. In practice this continued for the cockpit into the war years, certainly for early production Ki-61, whereas aotake continued to be applied to other parts of the interior. When the application of aotake to interior surfaces was discontinued in early 1943 in order to to speed production cockpits began to be painted in other colours in a more haphazard manner, including the # 1 grey green and another darker grey green paint similar to that used for Hayate propellers.     

The grey blue paint was also found inside the wing sections of the hybrid remains of Ki-61-I Ko/Otsu c/n 379/640 (379 constructed in Sep 1943 and 640 in Nov 1943), although the wheel wells appeared to be painted in a lighter grey colour, unspecified. Whether the lighter grey paint was very badly degraded, chalked or faded grey blue is now impossible to say. The problem, as referenced before, is that restorers take an inconsistent approach to measuring and recording extant paint in surviving airframes, often just stating that new paint 'matches the original' without actual providing colour values for it, the original paint being destroyed in the process. And laying standard paint swatches against the original paint surface and photographing them is not a valid scientific method for identifying the original colour value(s).