If your ecobee4 hasn’t correctly detected the wiring during the guided setup, you can manually configure the correct wiring.
During the guided setup, there will be a screen displaying the wires your ecobee has detected. These wires will be highlighted in white. It will ask you whether this information is correct, if there is an error select “no.” You can then either remove your ecobee4 from the wall to adjust the wiring or you can manually configure the missing wires. Tap the wire-terminal that has an undetected wire, it will turn white. Select continue, then follow the remaining steps to complete the guided setup.
If you notice a wiring error after you have already completed the guided setup, tap MENU and select SETTINGS. Select EQUIPMENT then WIRING to see which wires your thermostat has detected.
If you notice an error, tap BACK, then select RE-CONFIGURE EQUIPMENT and follow the guided set up to re-configure your ecobee and manually configure the wiring.