Cable colour codes

These colour codes are offered as guidance in allocating circuits and investigating existing installations. Many installers abbreviate colours to their initial and last letters - Bk for Black, Bn for Brown. An alternative is to use the initial letter, but to avoid duplication, under this system Black is K, Brown is N and Grey is S (for Slate). BBC designed cables usually use Slate instead of Grey , but as the two colours are very similar, and are never both used in the same cable, they are effectively interchangeable. The BBC colour codes are explained in ED122 Guide to Wiring (stock code 0446493).

Where two colours are shown separated by a hyphen, the first colour is the primary colour, usually the base colour, with the second (and third where appropriate) applied as thin bands or stripes. Occasionally cables are manufactured with less of the primary colour showing than the secondary colour (sometimes within the same cable) but this should not lead to confusion. In the CW1308 standard the primary/secondary colours are rigidly defined, and the primary colour (shown in capitals) is always the base colour.

Multipair cables have repeated solid colours as primaries, and the pair number is identified by the colour of the other half of the twisted pair - care should be taken when preparing these cables to ensure the correct pairing is maintained.

IEC

Pair No. A-CORE B-CORE
1 White Blue
2 White Orange
3 White Green
4 White Brown
5 White Grey
6 Red Blue
7 Red Orange
8 Red Green
9 Red Brown
10 Red Grey
11 Black Blue
12 Black Orange
13 Black Green
14 Black Brown
15 Black Grey
16 Yellow Blue
17 Yellow Orange
18 Yellow Green
19 Yellow Brown
20 Yellow Grey
21 White - Blue Blue
22 White - Blue Orange
23 White - Blue Green
24 White - Blue Brown
25 White - Blue Grey
26 Red - Blue Blue
27 Red - Blue Orange
28 Red - Blue Green
29 Red - Blue Brown
30 Red - Blue Grey
31 Black - Blue Blue
32 Black - Blue Orange
33 Black - Blue Green
34 Black - Blue Brown
35 Black - Blue Grey
36 Yellow - Blue Blue

Belden

Pair No. A-CORE B-CORE
1 Black Red
2 Black White
3 Black Green
4 Black Blue
5 Black Yellow
6 Black Brown
7 Black Orange
8 Red White
9 Red Green
10 Red Blue
11 Red Yellow
12 Red Brown
13 Red Orange
14 Green White
15 Green Blue
16 Green Yellow
17 Green Brown
18 Green Orange
19 White Blue
20 White Yellow
21 White Brown
22 White Orange
23 Blue Yellow
24 Blue Brown
25 Blue Orange
26 Brown Yellow
27 Brown Orange
28 Orange Yellow
29 Violet Orange
30 Violet Red
31 Violet White
32 Violet Dark Green
33 Violet Light Blue
34 Violet Yellow
35 Violet Brown
36 Violet Black

KSM & BSM

Pair No. A-CORE B-CORE
1 Blue Blue - White
2 Orange Orange - White
3 Green Green - White
4 Brown Brown - White
5 Grey Grey - White
6 Blue Blue - Red
7 Orange Orange - Red
8 Green Green - Red
9 Brown Brown - Red
10 Grey Grey - Red
11 Blue Blue - Black
12 Orange Orange - Black
13 Green Green - Black
14 Brown Brown - Black
15 Grey Grey - Black
16 Blue Blue - Yellow
17 Orange Orange - Yellow
18 Green Green - Yellow
19 Brown Brown - Yellow
20 Grey Grey - Yellow
21 Blue Blue - Violet
22 Orange Orange - Violet
23 Green Green - Violet
24 Brown Brown - Violet
25 Grey Grey - Violet
26 Blue - White White
27 Orange - White White
28 Green - White White
29 Brown - White White
30 Grey - White White
31 Blue - White Red - White
32 Orange - White Red - White
33 Green - White Red - White
34 Brown - White Red - White
35 Grey - White Red - White
36 Blue - White Black - White
37 Orange - White Black - White
38 Green - White Black - White
39 Brown - White Black - White
40 Grey - White Black - White
41 Blue - White Yellow - White
42 Orange - White Yellow - White
43 Green - White Yellow - White
44 Brown - White Yellow - White
45 Grey - White Yellow - White
46 Blue - White Violet - White
47 Orange - White Violet - White
48 Green - White Violet - White
49 Brown - White Violet - White
50 Grey - White Violet - White

KHJ

Pair No. A-CORE B-CORE
1 Blue White
2 Orange White
3 Green White
4 Brown White
5 Grey White
6 Blue Red
7 Orange Red
8 Green Red
9 Brown Red
10 Grey Red

Category

Pair No. A-CORE B-CORE
1 Blue White - Blue
2 Orange White - Orange
3 Green White - Green
4 Brown White - Brown

BT CW1308

Pair No. A-CORE B-CORE
1 WHITE - Blue BLUE - White
2 WHITE - Orange ORANGE - White
3 WHITE - Green GREEN - White
4 WHITE - Brown BROWN - White
5 WHITE - Grey GREY - White
6 RED - Blue BLUE - Red
7 RED - Orange ORANGE - Red
8 RED - Green GREEN - Red
9 RED - Brown BROWN - Red
10 RED - Grey GREY - Red
11 BLACK - Blue BLUE - Black
12 BLACK - Orange ORANGE - Black
13 BLACK - Green GREEN - Black
14 BLACK - Brown BROWN - Black
15 BLACK - Grey GREY - Black
16 YELLOW - Blue BLUE - Yellow
17 YELLOW - Orange ORANGE - Yellow
18 YELLOW - Green GREEN - Yellow
19 YELLOW - Brown BROWN - Yellow
20 YELLOW - Grey GREY - Yellow
21 VIOLET - Blue BLUE - Violet
22 VIOLET - Orange ORANGE - Violet
23 VIOLET - Green GREEN - Violet
24 VIOLET - Brown BROWN - Violet
25 VIOLET - Grey GREY - Violet
26 PINK - Blue BLUE - Pink
27 PINK - Orange ORANGE - Pink
28 PINK - Green GREEN - Pink
29 PINK - Brown BROWN - Pink
30 PINK - Grey GREY - Pink

DEF STAN 61-12

Core No. DEF STAN 61-12
1 Red
2 Blue
3 Green
4 Yellow
5 White
6 Black
7 Brown
8 Violet
9 Orange
10 Pink
11 Turquoise
12 Grey
13 Red - Blue
14 Green - Red
15 Yellow - Red
16 White - Red
17 Red - Black
18 Red - Brown
19 Yellow - Blue
20 White - Blue
21 Blue - Black
22 Orange - Blue
23 Green - Blue
24 Grey - Blue
25 Yellow - Green
26 White - Green
27 Green - Black
28 Orange - Green
29 Grey - Green
30 Yellow - Brown
31 White - Brown
32 Brown - Black
33 Grey - Brown
34 Yellow - Violet
35 Violet - Black
36 White - Violet
37 *See note below

*Note: The DEF STAN 61-12 code becomes very curious after 36 cores. It operates in "layers", with the first core in the layer red, the second blue, and the rest white. The next "layer" will then start with red, then blue, then all white again. The basis is that the cores will be recognised by their physical position in the lay.