Is there any way to see whether the system is currently heating/cooling/standby? In other words: what is the color of the display of the thermostat? (red/blue/black)?
I could not see a value for that in the documented API. Can I derive it from a combination of factors?
for example, if hvac-mode=heat and target-temp > ambient then it must be heating...
Unfortunately Nest do not give this information.
Update
Nest Thermostats now has a hvac_state that returns if the device is off, heating, or cooling.