I have hue light bulbs in almost every lamp in my house. While you can switch hue bulbs on and off like normal light bulbs, you can not use their special features if they are disconnected from the power supply. For example, you can set an alarm in the morning which simulates a sunrise. But then in the middle of the night you have to go to the toilet. You could unlock your phone, turn them on, go to the toilet, go back, unlock your phone and turn them off. This is very inconvenient. But when you switch the lights off using a normal switch, the lights will not fake the sunrise, because the lack of power.
Best case scenario: you just get up, go to the toilet. A motion sensor tells your lights to fade to a very low brightness which is comfortable for your sleepy eyes. After some time without motion detected the lights turn off.
Of course the system has to check first whether the target lights are off before you trigger this process. But these are details. My system will be a modification of the Raspberry Pi Parent Detector.
I ordered a Raspberry Pi, a PIR motion sensor and some female-female jumper to connect both.
As soon as the items are shipped I will post an update.