Mitsubishi Zero and the "Ameiro" color ...

Let me try to post an aviation-related message among this
rec.aviation.political.ihateyou.military messages that have taken over
the board. :-)

There's always a discussion among scale modellers regarding the
correct colors for IJN Mitsubishi Zeros. One of them is about the
existance or not of a color called "Ameiro". Some say it was the
actual color used on some Zeros, while others say it was not a color,
but actually a varnish applied over the original IJN Gray (or white)
that became yellowish with time.

Does anyone have any info on that?