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. Insulator colors are to be easily distinguishable as red, yellow, and green. Tables 2 and 3 show complete descriptions of the lamps involved for the T1-3/4 and T1 lamps respectively. New lamp part numbers may be added by a revision process as required.