25 pair color code

The 25 pair color code is a color code used to identify individual conductors in a kind of electrical communication wiring known as twisted pair cables. The colors are applied to the insulation that covers each conductor. The first color is chosen from one group of five colors and the other from a second group of five colors, giving 25 combinations of two colors.

The first group of colors is, in order: 'white, red, black, yellow, violet'.

The second group of colors is, in order: 'blue, orange, green, brown, slate'.

(The color violet is more commonly called purple, but in the telecommunications industry it is always referred to as violet. Similarly, slate is a particular shade of gray.)

One of the most common uses of the codes is in Category 5 computer network wiring, as used for structured cabling for switched Ethernet installations, where only the codes for the first four pairs are used.

Sometimes each wire in a pair will have a colored stripe matching the color of its paired wire. This makes it easy to identify which pair a given wire belongs to. Otherwise, to determine which pair a wire belongs to one has to note which color codes are physically twisted together.

Pair #	First wire	Second wire
1	White	Blue
2	White	Orange
3	White	Green
4	White	Brown
5	White	Slate
6	Red	Blue
7	Red	Orange
8	Red	Green
9	Red	Brown
10	Red	Slate
11	Black	Blue
12	Black	Orange
13	Black	Green
14	Black	Brown
15	Black	Slate
16	Yellow	Blue
17	Yellow	Orange
18	Yellow	Green
19	Yellow	Brown
20	Yellow	Slate
21	Violet	Blue
22	Violet	Orange
23	Violet	Green
24	Violet	Brown
25	Violet	Slate