You’ll need to have a switch node (on and off) and then a change node.
Stick this in front of your hue light, forgetting the timer node for now.
[{"id":"d4cc4af7.cc52a8","type":"change","z":"7a8ff9fc.5b6ee8","name":"OFF","rules":[{"t":"set","p":"payload","pt":"msg","to":"false","tot":"bool"}],"action":"","property":"","from":"","to":"","reg":false,"x":810,"y":2080,"wires":[["64412b46.7aff44"]]},{"id":"64412b46.7aff44","type":"hue-light","z":"7a8ff9fc.5b6ee8","name":"Laundry (white)","bridge":"5e6fe1ca.85689","lightid":"42","colornamer":true,"skipevents":false,"universalevents":false,"x":980,"y":2060,"wires":[[]]},{"id":"c0cd601c.087d8","type":"change","z":"7a8ff9fc.5b6ee8","name":"100%","rules":[{"t":"set","p":"payload","pt":"msg","to":"{\"on\":true,\"brightness\":100}","tot":"json"}],"action":"","property":"","from":"","to":"","reg":false,"x":810,"y":2040,"wires":[["64412b46.7aff44"]]},{"id":"5e6fe1ca.85689","type":"hue-bridge","name":"Philips hue","bridge":"192.168.1.221","key":"76VF5utXrkJ9PftxiZgEDKW3dFB67Mv8H1Op4RQA","interval":"3000","disableupdates":false}]