 Building wiring under the US National Electrical Code and the Canadian Electrical Code is identified by colors to show energized and neutral conductors, grounding conductors and to identify phases.Other color codes are used in the UK and other areas to identify building wiring or flexible cable wiring.Mains electrical wiring, both in a building and on equipment was once usually red for live, black for neutral, and green for earth, but this was changed as it was a hazard for color-blind people, who might confuse red and green; different countries use different conventions.