A Brief History:
210-5. Color Code. Where installed in raceways, as aluminum sheathed cable, as open work, or as concealed knob-and-tube work, the conductors of multiwire branch circuits connected to the same system shall conform to the following color code. Three-wire circuits - one black, one white, one red; four-wire circuits - one black, one white, one red, one blue; five-wire circuits - one black, one white, one red, one blue, one yellow. Where more than one multiwire branch circuit is carried through a single raceway the ungrounded conductors of the additional circuit may be of colors other than those specified. All circuit conductors of the same color shall be connected to the same ungrounded feeder conductor throughout the installation.
This passage of 210-5 is unchanged from previous editions of the Code. Text was added in '68 after the quote above to cover the color of the grounding conductor, where used.
'71 NEC 210-5. Color Code for Branch Circuits. The section is broken into parts (a) Grounded Conductor, (b) Grounding Conductor & (c) Ungrounded Conductor. Section 210-5(c) Ungrounded Conductor
itself no longer specifies colors, except to exculde the colors used in (a) & (b), and is followed with a fine print note:
It is recommended for a basic single wiring system that the following colors be used: 3-wire circuits, 1 black, 1 white and 1 red; 4-wire circuts, 1 black, 1 white, 1 red, and 1 blue.
'75 NEC 210-5(c) the FPN is deleted and the wording is simplified to:
210-5 Color Code for Branch Circuits
(c) Ungrounded Conductor. Ungrounded conductors of different voltages shall be of different color or indentified by other means.
What was the CMP reasoning for the removal of the color code?
[This message has been edited by ElectricAL (edited 01-22-2003).]