Alarm Install Wiring Diagram - This Arduino based Real time clock is a digital clock to display real time using a RTC IC DS1307 which works on I2C protocol. Real time clock means it runs even after power failure. When power is reconnected, it displays the real time inrespective to the time and duration it was in off state. What you will learn in Thermostat Wiring Colors Code. article:. What thermostat wire color is likely to go to which terminal on the thermostat. Basic electrical safety and standards for wiring color.