Justin's model is a beautiful example of the a Nakajima Zero. Mitsubishi Zeros were a little bit different. I found this forum, there's some really good information here: 

https://www.britmodeller.com/forums/index.php?/topic/235013930-mitsubishi-vs-nakajima-zero/

There as far as know no brown was used on navy aircraft, only army and the Zero was only navy. Early war aircraft were grey overall and later were painted green over grey. 

Bob D

I am sure this has been asked before, but I am still cofused. Did they ever paint their planes Grey? Was Brown a navy color? Which Green matches their color best. And finally which company makes the closest match?

 

I painted this using the Vallejo IJN Green listed above in the set in the bottom link....

as for your question about "which company makes the closest match?", well, that depends on what your final goal is.  as you can see on my Zero, I used the black basing techniques, so there is a variation in the paint, there is weathering, there is chipping...my question to you is what is your end goal...what are you comparing it to?  Are you building solely for yourself, or are you building to win awards at shows?

Painting an aircraft from 75 years ago is different, accuracy wise, than matching engine color on a vintage Ford or Chevy.

Good Luck and post pics!

As the guys pointed out those sites are a good start. Japanese colours are a confusing mess at best. What sort of aircraft were you looking to build? It might be best to start there.

https://acrylicosvallejo.com/en/producto/hobby/sets/air-war-en/imperial-japanese-army-ija-colors-pre-war-to-1945-71152-es/

https://acrylicosvallejo.com/en/producto/hobby/sets/air-war-en/imperial-japanese-navy-ijn-colors-pre-war-to-1945-71169-es/

Tamiya X13 is the best aotake colour too.

For interior colours you should look at other paints from the Model Air range. The sets just cover the exterior. Check out my Ki-45 Nick and J7W1 Shinden to see these paints used