Wiring color codes are the identification colors that color the wires in your automobile. For example, if you have a British car the blue, blue and white , and blue and red wires are for the headlights. The red and white wires are for the instrument lights, and the green and white and green and red wires are for the turn lights. The color code simply identifies what that wire does. Could you imagine if all of the wires were the same color. You couldn't identify anything in a harness.