How to create graph for pool temperature but change color when pool heater is on? (re: changing graph color depending on another value?)

In my influx database I have data for my current pool temperature and also the power (wattage) from my pool heater.

The pool heater is typically at 0 watts but if it’s above 0 watts it’s considered “on”.

I’d like to graph my pool temperature but somehow indicate if the pool heater was turned on during that time period. (i.e. change the color of the area under the graph, or something similar).

Can anybody point me in the right direction?