APWA Color Code
The American Public Works Administration (APWA®) is a non-profit organization of companies, public works agencies, and individuals who created the Uniform Color Code – the universal marking guideline that should be used by all professional underground utility locating companies. It provides unanimous understanding of the marking of underground utilities for both construction and engineering projects. It helps to prevent accidents and damage to subsurface utilities by contractors, excavators, and anyone else digging around underground utilities.
For more detailed information about what the marks mean, take a look at the CGA’s Guidelines for Operator Facility Field Delineation.