my latest is my first World War One kit since i was a kid... the 1/32 Encore/Roden McCudden SE5a.
that Mr. Paint PC-10 looks like exactly a color that could have one guy swearing it's green and another swearing it's brown, and neither would be wrong, at least as far as i can tell from a photo on the internet.
also it looks like a color that could be made from "yellow ochre (40 lbs), umber (30 lbs), red ochre (40 oz), Chinese blue (25 oz for darkening) and lampblack ("few ounces" only where further darkening was required)," as far as i know the only documented official PC-10 formula.
I'll probably give it a try.