On city streets today, you can see the spectrum of safety colors that have been formalized and revised over the decades by the American National Standards Institute: RED: electric power lines, cables, and conduit ORANGE: telecommunications, alarm and signal lines YELLOW: gaseous or combustive materials including natural gas, oil, petroleum, and steam GREEN: sewers and drain lines BLUE: potable water PURPLE: reclaimed water, irrigation, or slurry lines PINK: temporary markings, unidentified facilities, or known unknowns WHITE: proposed excavation areas, limits, or routes
