Label Styles

It would be awesome of HA supported a universal option that allowed you to apply at least some basic styles to particular entities in the UI. For example:

- platform: mqtt
  state_topic: "/sensor/rtl433"
  name: outdoor_temperature
  unit_of_measurement: '°C'
  value_template: '{% if ( is equalto 9134) %} {{ value_json.temperature_C }} {% endif %}'
  expire_after: 600
  font_style: bold

Basically what I am looking for is a way to visually distinguish certain sensors as “local” readings vs. some sort of outside data. For example, I want it to be clear that in this case the temperature sensor I’m looking at is based on data coming from my own sensor instead of something like Dark Sky.

I’m not real particular on the exact nature of the distinction, but font style seems the easiest? Icon color would also be nice which I believe is already a feature request?