I'm asking because I'd like to know if there is any guide to vending in these forums. It would help as a reminder to know what vending machines give out items from which stores, and...why are vending machines color coded? For example, why does Grave Digger give out so many green items?

has a guide on their profile about what machines give what items

Thanks! It seems "green" and "brown" are new keywords that the Gravedigger now gives out.