200.7 Use of Insulation of a White or Gray Color or
with Three Continuous White Stripes.
(C) Circuits of 50 Volts or More. The use of insulation
that is white or gray or that has three continuous white
stripes for other than a grounded conductor for circuits
of 50 volts or more shall be permitted only as in (1)
through (3).
(1) If part of a cable assembly and where the insulation is
permanently reidentified to indicate its use as an ungrounded
conductor, by painting or other effective
means at its termination, and at each location where the
conductor is visible and accessible. Identification shall
encircle the insulation and shall be a color other than
white, gray, or green.
(2) Where a cable assembly contains an insulated conductor
for single-pole, 3-way or 4-way switch loops and
the conductor with white or gray insulation or a marking
of three continuous white stripes is used for the
supply to the switch but not as a return conductor from
the switch to the switched outlet. In these applications,
the conductor with white or gray insulation or with
three continuous white stripes shall be permanently reidentified
to indicate its use by painting or other effective
means at its terminations and at each location
where the conductor is visible and accessible.
(3) Where a flexible cord, having one conductor identified
by a white or gray outer finish or three continuous
white stripes or by any other means permitted by
400.22, is used for connecting an appliance or equipment
permitted by 400.7. This shall apply to flexible
cords connected to outlets whether or not the outlet is
supplied by a circuit that has a grounded conductor.
All 3 deal with cable & cords, not THHN in a raceway, so they do not apply.