For US built aircraft that is easy- MM makes Insignia Blue, Insignia Red, and Insignia White that was used for the markings on aircraft made for US and Lend Lease use. Now UK built aircraft used the original BSC shades which were a tad bit different, especially the Red which was darker and with a hint of brown.
As far as Japanese colors go, that is gonna be more up in the air as to which paint shade is a good starting point.
F is for FIRE, That burns down the whole town!
U is for URANIUM... BOMBS!
N is for NO SURVIVORS...
- Plankton
LSM