Got it. Many thanks.
Apparently, the option is ‘–state-cover-active-color: var (–red-color)’
type: entities
entities:
- entity: cover.main_garage
type: simple-entity
card_mod:
style: |
:host {
{% if states('cover.main_garage') != 'closed' %}
--state-cover-active-color: var(--red-color);
color: red;
{% endif %}
}
gives me:
Which is just what I wanted.
Many thanks for your patience.