What Three colors are underground conductors not permitted t

What Three colors are underground conductors not permitted to be?

Solution

An insulated grounded conductor larger than 6 AWG shall be identified by one of the following means:

(1) By a continuous white or gray outer finish.
(2) By three continuous white stripes along its entire length on other than green insulation.
(3) At the time of installation, by a distinctive white or gray marking at its terminations. This marking shall encircle the conductor or insulation.