The following car stereo wiring diagrams show the different color codes used in any car's entertainment system. As we see here, yellow is connected to a 12V battery, red is connected to 12V Ignition, Black is for Chassis Ground (-), Black/White is for factory amplifier ground, and more. It should be noted here that even though the Electronics Industry Association standardizes these color codes, these codes differ from the wiring colors used by the vehicle manufacturers. That is why it is always recommended to refer to your stereo owner's manual for specific wiring details before making any real-time connections to your car stereo wiring system.