found the answer to my own question - I’m posting it here as there are quite a few similar unanswered posts on this forum - hopefully this will help someone:
binary_sensor:
- platform: homeassistant
id: workshop_alarm
entity_id: automation.workshop_alarm
internal: true
light:
- platform: fastled_clockless
id: led
name: ${friendly_name}
pin: GPIO27
chipset: SK6812
num_leds: 1
rgb_order: grb
restore_mode: ALWAYS_ON
on_turn_on:
then:
- if:
condition:
binary_sensor.is_on: workshop_alarm
then:
- light.turn_on:
id: led
red: 100%
green: 0%
blue: 0%
else:
- light.turn_on:
id: led
red: 0%
green: 100%
blue: 0%