Yes, standards are referenced in regulations - no argument there. The key is that these regulations apply to people that manufacture containers. We have yet to see any rule that says a consumer must use the containers and must not use any other container.
My thought to your question Steve might be state and local laws that prohibit non-approved containers. I know of one city (Marshfield) in my state that governs the amount of fuel that you can have in your house, attached garage or detatched garage by municipal code. That city also states, "approved containers and no milk jugs". Most states that have adopted NFPA 30, I do not know of a state that hasn't, then these same requirements will exist for everyone. Inside NFPA 30 they also have a container section.
My state only has regulations on the containers, WI Admin Code 10.28, WI Admin Code 48.10, and WI Statute 168.11. My states code prohibits the use of non-approved containers and states the containers that are approved must be UL classified or listed. The last part denotes the color.
In order for a manufacturer to be UL classified or listed for Wisconsin they must meet the UL guide on consumer-use fuel cans which states:
Gasoline (red) Investigated to ASTM F852, "Standard Specification for Portable Gasoline Containers for Consumer Use," and intended for flammable spark-ignition automotive fuels such as gasoline and low-blend ethanol (max E10), compliant with ASTM D4814, "Standard Specification for Automotive Spark-Ignition Engine Fuel," and gas/oil mixtures for two-cycle engines. Dual-compartment cans are intended for separate storage of gas and oil.
Diesel (yellow) Investigated to ASTM F976, "Standard Specification for Portable Kerosene and Diesel Containers for Consumer Use," and intended for combustible compression-ignition automotive fuels such as diesel and low-blend biodiesel (max B5), compliant with ASTM D975, "Standard Specification for Diesel Fuel Oils."
Kerosene (blue) Investigated to ASTM F976 and intended for combustible heating-appliance fuels such as K1 or K2, compliant with ASTM D3699, "Standard Specification for Kerosene."
According to David at Wisconsin's Bureau of Petroleum Services, "service stations are not allowed to sell fuel to anyone putting fuel in non-approved containers. Many do but if they are caught by federal or state inspectors they can be shut-down and/or fined."
I was looking through the federal register, Federal Register /Vol. 72, No. 37, on the EPA changes for these consumer fuel cans and they mention that the colors are red, yellow, and blue.
According to Neil at the DOT (Federal) a "DOT approved can" must meet all 49 CFR requirements and be certified by a national testing laboratory. He said that as far as color and a few other requirements on 5 gallon and less personal use containers the DOT regulates these through the national lab certifications. He said to be DOT approved you must have a national laboratory certification, but to get a lab to certify you must have an industry certification ANSI/ASME first.