Sorry to disappoint you but there is no such thing as an "Industry wide Color Code for Commodities".
The closest you will come to it is in OSHA regulations where they recommend Red for Fire Water and Green for Oxygen. These are more Safety related than Commodity related.
Your company or Client (whichever is applicable) is in a position to select whatever they want.
I predict however, that you will get lots of suggestions here bases on alleged"Industry Standards".