I am going to install a Kahtec blinking smart stop light module and some other items some day (like new DRL lights and led foglights. I was wondering if there is a 'standard' color code system for automotive wiring so it is easier to tell positive from negative. For instance, I have 2 wires, one all white and one white with black stripe. In another instance, I have one black wire and one purple wire. Which is which?