Yes, that can be done like this:
type: custom:mushroom-light-card
entity: light.office_light
show_brightness_control: true
card_mod:
style: |
mushroom-shape-icon {
{{ '--card-mod-icon: mdi:lightbulb;' if is_state(config.entity, 'on') else '--card-mod-icon: mdi:lightbulb-off;' }}
--icon-color-disabled: rgb(var(--rgb-green));
--shape-color-disabled: rgba(var(--rgb-green), 0.2);
}