cockpit color for a nakajima b5n "kate"?

well there is a lot of answers to that question... www.j-aircraft.com has a lot of good info on WWII japanese AC. The aircraft touted as most accurate of the reconstructions had a color that looked like RAF interior green mixed 4:1 or so with Dk Green.

I do know the different manufacturers had different shades but j-aircraft.com may help you straighten this out... I've been using it exclusively as a resource for japanese AC as it is very well researched.

MM IJN Interior green is plenty close for Nakajima aircraft, and I think you'll get a similar answer on j-aircraft.com. This is getting into that territory that's tantamount to nailing the proverbial jellyfish to a tree. But, oddly, the most recent and reliable research shows the Nakajima color to be similar to the British interior gray-green, while Mitsubishi interiors are almost a dead-on match for Model Master IJA exterior green.
I just finished a cockpit for a Mitsubishi A6M3 Type 22 Zero, and when I started, using an Eduard color PE set for it, I found myself cursing that the colors of the PE wouldn't be correct for the real interior color, at least, real according to the latest research. Well, surprise -- Eduard was smarter than I gave them credit for, because their color parts are an exact match for the MM IJA green, which is a match for the Mitsubishi interior color. Is this confusing enough for you?
TOM