This document defines the method for voltage identification by use of color coded insulators at the base of the lamp. Table 1 shows lamp part numbers and corresponding insulator colors.The part numbers shown are for example purpose only, as an option.Insulator colors are to be easily distinguishable as green, yellow, red, and white. Additional colors may be added by a revision process as required.SAE ARP 4156 has superceded SAE AS 4156.
