Home electrical wiring uses a common color scheme, which is useful when installing or maintaining a reliable electrical design in a household. Different colors represent different electrical currents and will be found in certain groups of home applications.
Black and red wires are used as hot wires. Black and red wires are found in switches and outlets.
Blue and yellow are also used to reference hot wires. They are more commonly used as travelers in three- or four-way switches and in some lights and fans.
White is typically used to represent a neutral wire. It has similar uses to a ground wire.
Green and bare copper wires are commonly used only for the ground wires.
These colors are the most common in home electrical design, but be careful to always check by using a multimeter before doing any work on wires.