You can delete a smart device from your Philips Hue system via your Hue account. To revoke permissions from a smart device, go to www.philips-hue.com, click Account, and then log in to your account. Once you are logged in, click Applications at the top of the page. This will display the devices that are currently connected to your Hue system. From there, you can click Deactivate to remove the device.