Utility Flag Color Code

Utility color codes are used to identify existing underground utilities in construction area, to protect them from damage during the project. Colored lines and flags are used to mark the underground location and the type of utility.

It’s also common for location services to use temporary chalk paint to mark utilities. 

To have utilities identified, contact 811 (Call Before You Dig) by phone or online.

Color Codes

Flag Color
Blue Used for potable water.
Green Used for sewers & drain lines.
Orange Used for communications, alarm, cable TV, signal lines, cables & conduit.
Pink Used for temporary survey markers.
Purple Used for reclaimed water, irrigation & slurry lines.
Red Used for electric power lines, cables, conduit & lighting cables.
White Used for proposed excavation.
Yellow Used for gas, oil, steam, petroleum & gaseous materials.