Updating old Lennox thermostat - wiring confusion
It appears that you have a thermostat that is designed to control a standard split-system heat pump. However, the wiring color code does not follow what I would call a conventional design. The control wiring for these heat pumps are fairly sophisticated.  You may want to consult a Lennox dealer for help.  Or a standard HVAC dealer for help with the control wiring.  Good Luck.