Have a electrician hook it up. I tried and the colored wires did not match up. I called Honeywell and they suggested some wiring diagrams but that did not work either. I called a heating and cooling company that sent 2 different people to try to wire it correctly the second one was successful.
The 2 best thing about this thermostat for us are (1) the fact that the backlight turns off after an adjustment so that there is no sleep disturbance and yet the digital display of the room temperature is clear without the backlight, and (2) all functions are displayed on the face when it is touched unlike Nest and other digital thermostats. The wifi works well, and the ability to adjust the settings remotely with the Honeywell Home or Apple Homekit apps is very helpful for a weekend home. The Honeywell app did take several tries to connect with each of 2 of these thermostats we have installed in a 2 zone HVAC system, but it did connect after 2-3 attempts and some prompts about alternative approaches, and we have had no glitches since. All in all a terrific thermostat.
The configuration instructions are not intuitive. The device is not pairing with one of the most common android phone samsung and bundled (5g and regular) wifi, i had to unbundle my router set up and reconfigure some of existing devices due to that.