color coding autocad plant drawings

[country045]

I have an opertunity to update our food plant autocad drawings and was curious if anyone knows if there is a standard for color coding (air, water, nitrogen etc...)for food plants. or if someone could point me in the right direction for researching such information.
thanks

 

[PSE]

In the US, this is a good source of coding information.

http://www.nfpa.org/

ISO should be a reasonable place to look for international codes/standards.

http://www.iso.org/iso/en/ISOOnline.frontpage

Regards,