[BUG] Unable to display string from a template

[lgm42]

Hello, I' would like to indicate the color of the day (French Power provider). It can be Blue, White or Red. An entity provide it to me into the entity: 'sensor.rte_tempo_couleur_actuelle'

I would like to see this string into the home circle as a secondary info

So I make following configuration:

entities:
  home:
    subtract_individual: false
    secondary_info:
      entity: sensor.rte_tempo_couleur_actuelle
      display_zero: true
      template: '{{states(''sensor.rte_tempo_couleur_actuelle''}}'
...

And I obtained Following result:

My information is marked as a javascript object: '[Object:object]', but the template home assistant tools says that it is a string. Did I miss something ?

Desktop (please complete the following information):

• OS: Windows
• Browser: Chrome