How to store data in JSON file in Node-RED

@hazymat, I started out using a database for this sort of thing, storing the current state of each device and updating it at every change. Since the introduction of persistent storage, I have gone back to using a JSON file for the static information about my devices and a global variable to store state information. In your case, a JSON file with something like this could store the device description:

[{"device":"Light 1",
"zone":"bedroom1",
"name":"Wall Light"
"fitting":"wall",
"colour":"warmwhite"},
{"device":"Light 2", 
"zone":"bedroom1",
"name":"Ceiling Light",
"fitting":"ceiling",
"colour":"RGB"}]

You can read the file and pass the payload through a JSON node. You get an array of objects that can be saved as a global variable or run through a split node to get a message or variable for each device. It's easy to edit the JSON in a text editor to add a new device or modify an old one.