I vaguely recall seeing a photo of a bare metal aircraft in squadron colours in one of my books, but the text mentioned it was a hack used for target towing. We do have training N1K skins in the game and IIRC the justification was they may well have seen combat, what with all the US aircraft over Japan in 1945. Ideally though, I'd still prefer something that was part of a combat squadron. If I can't find a decent WW2 photo of a non-training bare metal Ki-43, then I may have to go with the 55th Sentai one. I don't have time to do the research on this at the moment though.
I have a profile of the Ki-43 with the bird emblem, but it is mottled green on top.