Electrical wiring color codes include black, red, green or bare, white, and blue or yellow. The color code indicates what a specific wire's function is.
Black wires are hot electric wires meaning that they are live and carrying a current. Red wires are also hot electric wires in 220- and 100-volt installations and in switch legs. Green or bare copper wire is ground wire and provides a safe grounding for electrical devices. Blue and yellow wires are also hot wires that are usually pulled in conduit. Blue wires are used as travelers while yellow wires are only used as switch legs. White wire is always neutral.