To make a field configurable, here's what you need to do
- Create a content-type with the correct name in the
System.Fields scope
- Add the fields you need like
PredefinedColors, Range or whatever
If you did everything correctly, the forms system automatically detecs the matching names in the input-field and the type you just created.
- Just test it - it should work - otherwise do troubleshooting
- Optionally you can also now export this type configuration and place it in the extensions folders