The array key is the raw field value and the array value is the desired colour.
The available colours are the default "base" colours from Tailwind, with the addition of black:
If a colour is not specified for a status, it will be displayed as grey.
The field is displayed similarly to the built-in Laravel\Nova\Fields\Boolean field, with the ability to have more than a true/false value, and different labels and colours defined.
(Same as detail.)
The indicator is not displayed on forms by default. If you choose to display it as a form field, the indicator is not editable and does not write back to the server, as it is intended to come from a read-only or derived model attribute.
If you do need an editable status field, you might want to add your own additional Laravel\Nova\Fields\Select field to your resource, referencing the same attribute name, and with onlyOnForms() set.