Indigo is super rare, almost non-existent for all the 15 cursor roles. Its here now.
The indigo cursor set is a very dark blue theme set of 15 cursor roles. Depending on the type and clarity of monitor that you use, those indigo cursors would appear black when previewed on dark contrast monitors such as the old CRT monitors.
The indigo cursor set would look its best when previewed on one of the latest monitors such as the latest Dell models.