Single core

 Natural colour of the compound

Three core

Coloured tape or thread (e.g.: red - yellow - blue)

According to BS 6883/BS 7917

Alternatives

1 core

Red or Black

White and numbered

2 cores

Red - Black

White and numbered

3 cores

Red - Yellow - Blue

White and numbered

4 cores

Red - Yellow - Blue - Black

White and numbered

Above 4 cores

black numbers on white background

Pair

Black - White

Triple

Black - White - Red

Quad

Black - White - Red - Blue

Pairs/Triples/Quads are numbered with numbers printed directly on the insulated conductors (1-1; 2-2; …) or buy numbered tape

MV power and control

Red

LV power and control

Black

Instrumentation and control

Grey

Other colours available on request