I almost forgot about this stuff:
http://www.whiteensignmodels.com/acatalog/index.html?http%3A//www.whiteensignmodels.com/acatalog/British_Army.html&CatalogBody
They have a 'modern British Army green' that should do the trick. Mind you, I've never used those paints so I have no idea as to their quality.
Cheers - Dan