Hi Bob,
give me a day or so and I'll put up some model paints useful for the range of PC10/PC12 Methuen values published variously by Ray Rimell, Ian Huntley and Ian Baker that are based on measured samples. Strictly none of these are 'green', rather yellow-olives through yellow-brown olives to brown-olives (i.e. black/white plus a 'yellow' or 'orange'). I've found it best to mix/choose colours in natural daylight as some of these paints can look 'green' under artificial light (including white strip light from bench-top modelling lamps) but correctly 'brown in real daylight. There are some unexpected examples.
Cheers,
Graham