Use the Track Display panel
 
 
 

The Track Display control panel lets you:

To turn on or off any of the track point display features, open the Display control panel under the Track task. For each display feature, you can select how it will display: Always, Selected (when a track point is selected), or Never.

To control the length of trace lines, use the Length Forward and Length Backward fields.

NoteIf track points are given a specific name, as opposed to the machine default name of trackedpoint#, then that track point can not be selected in the track points listing and Maya shows the following error message:
Error: More than one object matches the name:pebble

User named track points can be selected in the outliner.

Display colors

You can also specify the colors for tracked points and other display features. Double-click the color box to open the Maya Color Chooser. You can specify both an Inactive color (item not selected) and an Active color (item selected). The display features are:

Track Point

Colors used for track points and their labels at all times except in an error state.

Error

Colors used when a track point is in an error state, such as a poor tracking.

Trace Line

Colors used for trace lines, one for the backward line and one for the forward line.

3D Locator

Colors used for the 3D locators created by Live.

Constraint

Colors used for the objects and lines representing constraints.