I’m only aware of a method by using card_mod:
type: entities
show_header_toggle: false
state_color: true
entities:
- entity: light.flur
name: Flurlicht
secondary_info: true
card_mod:
style:
hui-generic-entity-row:
$: |
.info .secondary {color: red;}
.info .secondary::before {
content: "Garderobe changed at: {{ as_timestamp(states.light.garderobe.last_changed)|timestamp_custom('%d.%m.%y %H:%M', true) }}";
color: green;
}