System Configuration : Preferences : Display Preferences : Color Coding

Color Coding
Always Display Marker Colors
Lets you choose to view Marker colors in the Markers ruler, regardless of the settings you choose for Default Clip Color Coding.
MIDI Note Color Shows Velocity
When enabled, MIDI notes display varying shades of the assigned track color in MIDI notes view in the Edit window and in MIDI Editor windows. Notes with high velocities are darker and notes with lower velocities are lighter.
Default Track Color Coding Options
These color coding options determine the default color coding assignment for tracks in the Edit and Mix windows. The options are:
None
Turns off color assignment for tracks.
Tracks and MIDI Channels
Assigns a color to each track in the Mix or Edit window according to its voice or MIDI channel assignment.
Tracks and MIDI Devices
Assigns a color to each track in the Mix or Edit window according to its voice assignment or MIDI device assignment.
Groups
Assigns a color to each track according to its Group ID. If groups are suspended using the Suspend Groups command, the tracks color bars are not shown.
Track Type
Assigns a color to each track according to its type (audio, Auxiliary Input, Master Fader, VCA Master, MIDI, Instrument, or Video).
Default Clip Color Coding Options
These color coding options determine the default color coding assignment for tracks, Marker Locations, and clips residing in the track playlist and Clip List. The options are:
None
Turns off color assignment for clips. Clips are drawn with black waveform or MIDI notes on a light gray background.
Tracks and MIDI Channels
Assigns a color to each clip in the Edit window according to its voice or MIDI channel assignment.
Tracks and MIDI Devices
Assigns a color to each clip in the Edit window according to its voice assignment or MIDI device assignment.
Groups
Assigns a color to each clip according to the Group ID of its track. If groups are suspended using the Suspend Groups command, all clips display black waveforms or MIDI notes on a light gray background.
Track Color
Assigns a clip color based on the color assigned to the track.
Marker Locations
Assigns a unique color to each marker area in the Marker ruler, including the area preceding the first marker.
Clip List Color
Assigns a color to each clip based on its color in the Clip List.