What color represents water systems in common utility color coding?

• A. Red
• B. Blue
• C. Yellow
• D. Green

Answer: (B)

Color coding of utility lines helps crews quickly identify what kind of system a line or mark represents. Blue is the standard color used to denote water systems, including potable water supply and often irrigation lines, on maps and in field markings. This makes blue a clear cue to expect water-related infrastructure and helps prevent mistakes during digging or maintenance. Other colors are assigned to different systems—red for electrical or fire protection, yellow for gas or petroleum lines, and green for sewer or drainage in many codes—though exact mappings can vary by local standards, so always check the project’s legend.