Yes, they can. The Skyline lights change CCTs automatically according to the change of time after setting the circadian lighting mode on the smartphone Tuya App. And you can maintain the CCT you like as well. The App can be deleted once you set up the circadian lighting mode. The Skyline lights will keep working in the mode that you set up. It won't reset if you turn it on and off (don't turn it on and off three times in a row).