Electrical marking tapes are used to label and color code electrical wire and identify equipment. They are pressure-sensitive tapes resistant to water and a variety of contaminants, which make them suitable for general-purpose electrical work and insulating applications. Black electrical marking tapes are the most common because they are more resistant to ultraviolet (UV) radiation than other colors. They are primarily used for insulating wire both in and out of direct sunlight. Other colors are used to identify phases and voltage levels of various wire. Gray and white designates neutral wire; green with yellow stripes label ground wire; brown, orange, and yellow indicate high-voltage wire of three phases; and black, red, and blue indicate low-voltage wire of three phases.