Here's a link to page 4-24 on the Integrated Publishing site showing identifying color patterns for gas cylinders:

http://www.tpub.com/content/construction/14250/css/14250_98.htm

The subject of the identification of gas cylinders actually begins on page 4-23 and goes through 4-26.

Near the end of the subject on page 4-26, it states "For a complete listing of compressed gas cylinders, refer to MIL-STD 101B, “Color Code for Pipelines and for Compressed Gas Cylinders", which indicates a military standard. One paragraph refers to one of the charts as color codes for compressed gas cylinders most often found in a construction battalion or in a public works department where Seabee personnel are working. The article also goes on to state at the end that the commercial industry does not necessarily comply with these color codes. I think that there are no standard color codes for the commercial industry, because the color codes vary from supplier to supplier. Looks like there would be though, for obvious reasons. I remember a few years ago, there was a young man working in a paint booth for Freightliner. He hooked up to his respirator what he thought was oxygen but it was argon. Since argon is odorless and tasteless, the guy never knew the difference, and it killed him.