How to Interpret Temporary Marking of Underground Cabling and Pipes

Per the American Public Works Association:

UNIFORM COLOR CODING FOR UNIFORM TEMPORARY MARKING OF UNDERGROUND FACILITIES

WHITE - Proposed Excavation

PINK - Temporary Survey Markings

RED - Electric Power Lines, Cables,
Conduit and Lighting Cables

YELLOW - Gas, Oil, Steam,
Petroleum or Gaseous Materials

ORANGE - Communication, Alarm
or Signal Lines, Cables or Conduit

BLUE - Potable Water

PURPLE - Reclaimed Water,
Irrigation and Slurry Lines

GREEN - Sewers and Drain Lines

Source: http://www.apwa.net/Documents/About/TechSvcs/One-Call/COLORCC.PDF