Guys, We have just been talking about this in the Chat-Rooms. We would like to have your colours for various services in your area. Considering that the US is a pretty wide varying place, in terms of codes and the like, please feel free to post you area's code in this respect.
Electric. Direct burial cables are generally just a black sheath, and may be laid with yellow/black marker tape above. Ducting for 240V supplies to residential properties is normally black, but red is used for higher voltages.
Telecoms/Cable TV/Fiber. Ducting may be gray, green, or black, depending upon area and installation. Old telephone cable ducts have no particular color ID.
Water supply. Modern piping is light blue, older PVC supply lines may be black. There are also many old steel and lead pipes in service with no particular identification.
Gas. Modern PVC is yellow. As with water, there are plenty of unidentified steel pipes still in use.
Drainage. The old glazed clay pipes are easy to identify by their size and brown/terracota color. Modern PVC drain pipes are normally either a similar brown color, or light gray.
[This message has been edited by pauluk (edited 03-01-2005).]