Before revision: 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.
After revision: ,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.