25 Pair Color Code

The 25-pair color code is used to identify individual conductors in a telecommunications twisted pair cable. The colors are marked on the conductors insulation. The first (primary) color is chosen from one group of five colors, and the other (secondary) color from a second group of five colors, giving 25 combinations of two colors. The tip color is always placed first, and pairs should never be split.

Note: Telecom equipment is "positive ground": tip is 0 VDC with respect to ground (earth), ring is -48 to -52 VDC.

Color Pairs:

White/Blue represents pair 1: eg, White with a Blue band is the tip, Blue with a White band is the ring.
Violet/Slate represents pair 25: eg, Violet with a Slate band is the tip, Slate with a Violet band is the ring.

Binder Groups:

For cables with more than 25 pairs, each 25 pair group is bundled with a colored binder following the same color code, eg: the blue/white binder group is the first, containing cable pairs 1 thru 25. This supports up to 625 pairs (25 binders x 25 pairs per bundle = 625 pairs), though Violet/Slate is not used (therefore, 600 pairs). With 100 pair cables (or less), often only the ring color is marked.

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