20-pair colour code (Australia)

The 20-pair colour code is a colour code used in Australia to identify individual conductors in a kind of electrical telecommunication wiring for indoor use, known as twisted pair cables. The colours are applied to the insulation that covers each conductor. The first colour is chosen from one group of five colours.

The combinations are also shown in the table below showing the colour for each wire ("1" and "2") and the pair number.

1-20			21-40			41-60			61-80			81-100
Pair #	First wire/ A Leg (L+)	Second wire/ B Leg (L-)	Pair #	First wire/ A Leg (L+)	Second wire/ B Leg (L-)	Pair #	First wire/ A Leg (L+)	Second wire/ B Leg (L-)	Pair #	First wire/ A Leg (L+)	Second wire/ B Leg (L-)	Pair #	First wire/ A Leg (L+)	Second wire/ B Leg (L-)
1	White	Blue	21	Yellow	Blue	41	Black	Blue	61	Violet	Blue	81	Red	Blue
2		Orange	22		Orange	42		Orange	62		Orange	82		Orange
3		Green	23		Green	43		Green	63		Green	83		Green
4		Brown	24		Brown	44		Brown	64		Brown	84		Brown
5		Grey	25		Grey	45		Grey	65		Grey	85		Grey
6		Blue-White	26		Blue-White	46		Blue-White	66		Blue-White	86		Blue-White
7		Blue-Orange	27		Blue-Orange	47		Blue-Orange	67		Blue-Orange	87		Blue-Orange
8		Blue-Green	28		Blue-Green	48		Blue-Green	68		Blue-Green	88		Blue-Green
9		Blue-Brown	29		Blue-Brown	49		Blue-Brown	69		Blue-Brown	89		Blue-Brown
10		Blue-Grey	30		Blue-Grey	50		Blue-Grey	70		Blue-Grey	90		Blue-Grey
11		Orange-White	31		Orange-White	51		Orange-White	71		Orange-White	91		Orange-White
12		Orange-Green	32		Orange-Green	52		Orange-Green	72		Orange-Green	92		Orange-Green
13		Orange-Brown	33		Orange-Brown	53		Orange-Brown	73		Orange-Brown	93		Orange-Brown
14		Orange-Grey	34		Orange-Grey	54		Orange-Grey	74		Orange-Grey	94		Orange-Grey
15		Green-White	35		Green-White	55		Green-White	75		Green-White	95		Green-White
16		Green-Brown	36		Green-Brown	56		Green-Brown	76		Green-Brown	96		Green-Brown
17		Green-Grey	37		Green-Grey	57		Green-Grey	77		Green-Grey	97		Green-Grey
18		Brown-White	38		Brown-White	58		Brown-White	78		Brown-White	98		Brown-White
19		Brown-Grey	39		Brown-Grey	59		Brown-Grey	79		Brown-Grey	99		Brown-Grey
20		Grey-White	40		Grey-White	60		Grey-White	80		Grey-White	100		Grey-White

The Australian standard specifies "Grey" in Tables B2 to B7. There are systems in other countries where "Slate" is used rather than "Grey". This is perceived as a minimisation of confusion between "Green" and "Grey" and their potential abbreviations: "G", "Gr", or "Gre". No such consideration is made for "Black", "Blue", or "Brown", or their potential abbreviations of "B", "Bl", or "Br".