Hue fades and lights bridge/hue.json
A switch in Home for each fade; turning it on runs the fade from its start. Bulbs marked to show in Home become lights with colour and Adaptive Lighting. It holds the Hue bridge's application key.
Edit the JSON instead (for the settings the form doesn't show; it keeps them as they are).
Saving checks the file the way the helper will at its next start. A restart puts it to use. Secrets are never shown: leave one empty to keep it.