Change font color based on sensor value?

I’m still using the old style MQTT sensor for a temperature sensor. It looks like this on my configuration.yaml. I’d like to make the font color change based on value. Say, normal if it’s between 67-75, red if it’s above 75, and blue if it’s below 67. I think I have to define a template of some sort, but I’m not sure how to go about it. I see templates based on is_state using binary sensors, but mine is a float value.

  - platform: mqtt
    state_topic: "/esp8266/temp_bedroom1"
    name: Bedroom 1 Temperature
    unit_of_measurement: 'F'

I’d also be interested in changing the icon based on the value too, if that’s something that’s doable?