I have got a LIDL LED bulb HG06106C and have connected it to Zigbee2Mqtt.
It works and I can change the colors.
My question is... I have Node-RED and can use the "node-red-contrib-zigbee2mqtt" add-on to get the state of my bulb, but how can I change the state for the bulb, so if the time is 18:00 then turn on the bulb with the color 255.0.0?
I'm not using Node-RED to HomeAssistant... but just to make some automations to handle my Zigbee2mqtt devices.
As you say, you can already "change the colors" then use an inject (or cron-plus) node set to trigger at 18:00 and send the same colour message to the device.
It's hard to say as i have no idea if your topic is correct.
Try installing mqtt explorer and subscribe to topic #, and then manually switch on the light, then in mqtt explorer you will see the payloads and topics required .