Apple Color 1.0 - Manual (Page 313)

Chapter 15 Geometry 313
Using Trackers in the Secondary, Color FX, and Geometry Rooms
Any adjustment in any room that can be animated by a tracker has a Use Tracker field.
Once you’ve processed a tracker, you can enter its ID number into this field to
automatically animate that adjustment based on the tracker’s motion path. Setting a
Use Tracker field to 0 resets that adjustment so that no tracker is used.