Mark Bannerman in the March 2013 issue Collector's Edition of Military Modelling builds the Renault R35 (I take it what you have here is a Hotchkiss but maybe the camo would have been similar. Here is a link to the issue I mean
http://www.myhobbystore.co.uk/product/162804/collectors%27-edition-military-vehicle-special-2013
If this interests you, I can let you know specifically what colours he used, as I have that issue myself. As you can probably see from the cover photo, however, there is a kind of reddish brown colour there that does not seem to be quite what your pic shows.