I'm sure there is room for improvement, but you do have control over brightness and contrast and color for all these attributes:
Window Background
Window text Text color
Rules in the Tempo view Vertical lines in the Tempo view used to mark time intervals
Major Rules Major lines used to mark larger intervals of time
Beat Rules Color of the Beat rule lines
Grid Rules Color of the Grid rule lines
Rules in the Track View Vertical lines in the Track view used to mark measure intervals
Values Color of selected events and tempo changes in the Tempo view
Drawing Colors used to show your drawing in the Piano Roll and Tempo views
Erasing Color used to show your erasing in the Tempo views
Lasso select Color of lasso select highlight
Markers Color of markers in time rulers
Pitch Markers Color of pitch markers in the Time Ruler
Loop Markers Color of loop point markers
Punch Record Markers Color of punch recording markers
Track View Time Ruler Digits Color of the Time Ruler markings
Time Ruler Tick Marks Color of the Time Ruler beat and measure lines
AudioSnap Pool Lines The color of the vertical lines in the Track view that show transient locations
Musical Snap Pool Lines The color of the vertical lines in the Track view that show Snap to Grid locations (when Add MBT to Pool is enabled)
Musical Snap Pool Markers The color of the markers in the Track view time ruler that show Snap to Grid locations (when Add MBT to Pool is enabled)
Clip Fades Color for the fade line and fade shading
Clip Zero Amplitude Lines Color for the line that marks a silent volume level for a clip
Snap Offset Markers Color of the Snap offset markers
Clip Gain Envelope Color of the Gain envelopes in clips
Clip Pan Envelope Color of the Pan envelopes in clips
Clip Velocity Envelope Color of velocity envelopes in clips
Selected Clip Color of clips that are currently selected
Muted MIDI Clip Data Color of the MIDI data in a muted area of a clip. Also used for the outline of event muted notes in the Piano Roll.
Folder Clip Background Color of an area of a folder clip where there is no data
Folder Clip Text Color of text label on a folder clip
Folder Line Color of the line on the left side of the Track pane connecting a track folder to the tracks that are contained in the folder
Record Preview Clip Background The background color in the Clips pane of an armed track
Recording Waveform Previews Color of the waveform in a clip during preview while recording
Bus Waveform Preview Color of the waveform that a bus’s or synth track’s output generates
Waveform Preview (>= 0dB) Color of the waveform in a clip during preview while recording if the amplitude is greater than or equal to 0dB
Input Quantize Record Preview Background The background color in the Clips pane of an armed MIDI track when Input Quantize is enabled
Frozen Track Background The background color of a frozen track in the Clips pane
Region FX Clip Background The background color of a Region FX clip.
Header The color of clip headers.
Header (selected) The color of selected clip headers.
Clip Background The background color of clips.
Clip Background (selected) The background color of selected clips.
Default Waveform Waveform color of audio clips.
Default Notes Note color of MIDI clips.
Audio Tracks 1, 11, 21...Foreground Foreground color of all audio tracks that end in the number “1” (1, 11, 21, etc.)
Audio Tracks 1, 11, 21...Background Background color of all audio tracks that end in the number “1” (1, 11, 21, etc.)
Audio Tracks 2, 12, 22...Foreground Foreground color of all audio tracks that end in the number “2” (2, 12, 22, etc.)
Audio Tracks 2, 12, 22...Background Background color of all audio tracks that end in the number “2” (2, 12, 22, etc.)
Audio Tracks 3, 13, 23...Foreground Foreground color of all audio tracks that end in the number “3” (3, 13, 23, etc.)
Audio Tracks 3, 13, 23...Background Background color of all audio tracks that end in the number “3” (3, 13, 23, etc.)
Audio Tracks 4, 14, 24...Foreground Foreground color of all audio tracks that end in the number “4” (4, 14, 24, etc.)
Audio Tracks 4, 14, 24...Background Background color of all audio tracks that end in the number “4” (4, 14, 24, etc.)
Audio Tracks 5, 15, 25...Foreground Foreground color of all audio tracks that end in the number “5” (5, 15, 25, etc.)
Audio Tracks 5, 15, 25...Background Background color of all audio tracks that end in the number “5” (5, 15, 25, etc.)
Audio Tracks 6, 16, 26...Foreground Foreground color of all audio tracks that end in the number “6” (6, 16, 26, etc.)
Audio Tracks 6, 16, 26...Background Background color of all audio tracks that end in the number “6” (6, 16, 26, etc.)
Audio Tracks 7, 17, 27...Foreground Foreground color of all audio tracks that end in the number “7” (7, 17, 27, etc.)
Audio Tracks 7, 17, 27...Background Background color of all audio tracks that end in the number “7” (7, 17, 27, etc.)
Audio Tracks 8, 18, 28...Foreground Foreground color of all audio tracks that end in the number “8” (8, 18, 28, etc.)
Audio Tracks 8, 18, 28...Background Background color of all audio tracks that end in the number “8” (8, 18, 28, etc.)
Audio Tracks 9, 19, 29...Foreground Foreground color of all audio tracks that end in the number “9” (9, 19, 29, etc.)
Audio Tracks 9, 19, 29...Background Background color of all audio tracks that end in the number “9” (9, 19, 29, etc.)
Audio Tracks 10, 20, 30...Foreground Foreground color of all audio tracks that end in the number “0” (10, 20, 30, etc.)
Audio Tracks 10, 20, 30...Background Background color of all audio tracks that end in the number “0” (10, 20, 30, etc.)
MIDI Tracks 1, 11, 21...Foreground Foreground color of all MIDI tracks that end in the number “1” (1, 11, 21, etc.)
MIDI Tracks 1, 11, 21...Background Background color of all MIDI tracks that end in the number “1” (1, 11, 21, etc.)
MIDI Tracks 2, 12, 22...Foreground Foreground color of all MIDI tracks that end in the number “2” (2, 12, 22, etc.)
MIDI Tracks 2, 12, 22...Background Background color of all MIDI tracks that end in the number “2” (2, 12, 22, etc.)
MIDI Tracks 3, 13, 23...Foreground Foreground color of all MIDI tracks that end in the number “3” (3, 13, 23, etc.)
MIDI Tracks 3, 13, 23...Background Background color of all MIDI tracks that end in the number “3” (3, 13, 23, etc.)
MIDI Tracks 4, 14, 24...Foreground Foreground color of all MIDI tracks that end in the number “4” (4, 14, 24, etc.)
MIDI Tracks 4, 14, 24...Background Background color of all MIDI tracks that end in the number “4” (4, 14, 24, etc.)
MIDI Tracks 5, 15, 25...Foreground Foreground color of all MIDI tracks that end in the number “5” (5, 15, 25, etc.)
MIDI Tracks 5, 15, 25...Background Background color of all MIDI tracks that end in the number “5” (5, 15, 25, etc.)
MIDI Tracks 6, 16, 26...Foreground. Foreground color of all MIDI tracks that end in the number “6” (6, 16, 26, etc.)
MIDI Tracks 6, 16, 26...Background Background color of all MIDI tracks that end in the number “6” (6, 16, 26, etc.)
MIDI Tracks 7, 17, 27...Foreground Foreground color of all MIDI tracks that end in the number “7” (7, 17, 27, etc.)
MIDI Tracks 7, 17, 27...Background Background color of all MIDI tracks that end in the number “7” (7, 17, 27, etc.)
MIDI Tracks 8, 18, 28...Foreground Foreground color of all MIDI tracks that end in the number “8” (8, 18, 28, etc.)
MIDI Tracks 8, 18, 28...Background Background color of all MIDI tracks that end in the number “8” (8, 18, 28, etc.)
MIDI Tracks 9, 19, 29...Foreground Foreground color of all MIDI tracks that end in the number “9” (9, 19, 29, etc.)
MIDI Tracks 9, 19, 29...Background Background color of all MIDI tracks that end in the number “9” (9, 19, 29, etc.)
MIDI Tracks 10, 20, 30...Foreground Foreground color of all MIDI tracks that end in the number “0” (10, 20, 30, etc.)
MIDI Tracks 10, 20, 30...Background Background color of all MIDI tracks that end in the number “0” (10, 20, 30, etc.)
Track View Active Outline Color of the border around the active pane in the Track view: if the Bus pane is active, it displays this color; if the Track pane is active, it displays this color.
Clips Pane Ellipse Color of dots which appear where there are no clips in the Clips pane
Selected Track Sets the color of any selected tracks
Track View Track Header Peak Text Color of the text on the right end of a track’s title bar that displays the peak level that the track’s audio meter measures
Track View Header Warning Text Color of the text described above when the track’s level is in danger of clipping
Peak Marker (< 0 dB) The color of the Peak Marker when amplitude peaks are less than 0dB
Peak Marker (>= 0 dB) The color of the Peak Marker when amplitude peaks are greater than or equal to 0dB
Peak Marker Text The color of the text on the Peak Marker
Vertical Measure Lines The color of vertical measure lines in the Clips pane
Vertical Beat Lines The color of vertical beat lines in the Clips pane
View Background (odd) The Clips pane background color for odd-numbered tracks/buses
View Background (even) The Clips pane background color for even-numbered tracks/buses
AudioSnap Marker Color of active AudioSnap transient markers
Disabled AudioSnap Marker Color of disabled AudioSnap transient markers
Selected AudioSnap Marker Color of selected AudioSnap transient markers
Maximum stretched AudioSnap Marker Color of maximum stretched AudioSnap transient markers
AudioSnap Pool Member Marker Color of AudioSnap transient markers that belong to the Pool
Aim Assist line Color of vertical line that follows the mouse pointer position when Aim Assist is enabled in the Track view
Track View Header Track Number Color of the track number in the track header
Track View Audio Track Name Background Color of background of audio track names in Track view
Track View Audio Track Name Text Color of text of audio track names in Track view
Track View MIDI Track Name Background Color of background of MIDI track names in Track view
Track View MIDI Track Name Text Color of text of MIDI track names in Track view
Track View Synth Track Name Background Color of background of Synth track names in Track view
Track View Synth Track Name Text Color of text of Synth track names in Track view
Track View Instrument Track Name Background Color of background of Instrument track names in Track view
Track View Instrument Track Name Text Color of text of Instrument track names in Track view
Track View Bus Name Background Color of background of Bus names in Track view
Track View Bus Name Text Color of text of Bus names in Track view
Track View Track Folder Name Background Color of the background for track folders in the folder name field
Track View Track Folder Name Text Color of the text for track folders in the folder name field
Track View Strip Background Background color outside the control fields in a track
Track View Control Background Background color inside the control fields in a track
Track View Control Text and Values Color of the text in Track view controls
Track View Disabled Control Text Color of disabled controls in a track
Track View Control Outline Color of the control outlines
Track View Control Borders Color of Track view control’s borders
Track View Current Control Outline Color of current Track view control outlines
Track View Strip Under Color of empty space in the Track pane
First controller/surface color choice Highlight color of any SONAR controls being controlled by the first control surface listed in Edit >Preferences > MIDI - Control Surfaces.
Second controller/surface color choice Highlight color of any SONAR controls being controlled by the second control surface listed in Edit >Preferences > MIDI - Control Surfaces.
Third controller/surface color choice Highlight color of any SONAR controls being controlled by the third control surface listed in Edit >Preferences > MIDI - Control Surfaces.
Fourth controller/surface color choice Highlight color of any SONAR controls being controlled by the fourth control surface listed in Edit >Preferences > MIDI - Control Surfaces.
Font for controller/surface channel number display Color of text in control surface channel display
Track View Trim Control Sets the color of the background in the trim control field
Track View Bus Input Pan Control Sets the color of this parameter’s automation envelope
Quick Group Sets the color that appears on controls that are part of a Quick Group
Track View Track Icons Background Color of space surrounding Track Icons in Track view
Track View Volume Control / Envelope Sets the color of this parameter’s automation envelope
Track View Pan Control / Envelope Sets the color of this parameter’s automation envelope
Track View MIDI Chorus Control / Envelope Sets the color of this parameter’s automation envelope
Track View MIDI Reverb Control / Envelope Sets the color of this parameter’s automation envelope
Track View Mute Envelope Sets the color of this parameter’s automation envelope
Surround Angle Envelope Color of automation envelope for surround angle
Surround Focus Envelope Color of automation envelope for surround focus
Surround LFE Send Control/Envelope Color of automation envelope for LFE send control
Surround Width Envelope Color of automation envelope for surround width
Front/Rear Balance Envelope Color of automation envelope for surround front/rear balance
Track View Bus Send Level 1, 9 Control / Envelope Sets the color of this parameter’s automation envelope
Track View Bus Send Level 2, 10 Control / Envelope Sets the color of this parameter’s automation envelope
Track View Bus Send Level 3, 11 Control / Envelope Sets the color of this parameter’s automation envelope
Track View Bus Send 4, 12 Level Control / Envelope Sets the color of this parameter’s automation envelope
Track View Bus Send Level 5, 13 Control / Envelope Sets the color of this parameter’s automation envelope
Track View Bus Send Level 6, 14 Control / Envelope Sets the color of this parameter’s automation envelope
Track View Bus Send Level 7, 15 Control / Envelope Sets the color of this parameter’s automation envelope
Track View Bus Send Level 8, 16 Control / Envelope Sets the color of this parameter’s automation envelope
Track View Bus Send Pan 1, 9 Control / Envelope Sets the color of this parameter’s automation envelope
Track View Bus Send Pan 2, 10 Control / Envelope Sets the color of this parameter’s automation envelope
Track View Bus Send Pan 3, 11 Control / Envelope Sets the color of this parameter’s automation envelope
Track View Bus Send Pan 4, 12 Control / Envelope Sets the color of this parameter’s automation envelope
Track View Bus Send Pan 5, 13 Control / Envelope Sets the color of this parameter’s automation envelope
Track View Bus Send Pan 6, 14 Control / Envelope Sets the color of this parameter’s automation envelope
Track View Bus Send Pan 7, 15 Control / Envelope Sets the color of this parameter’s automation envelope
Track View Bus Send Pan 8, 16 Control / Envelope Sets the color of this parameter’s automation envelope
Bus Send Angle 1, 9 Envelope Sets the color of this parameter’s automation envelope
Bus Send Angle 2, 10 Envelope Sets the color of this parameter’s automation envelope
Bus Send Angle 3, 11 Envelope Sets the color of this parameter’s automation envelope
Bus Send Angle 4, 12 Envelope Sets the color of this parameter’s automation envelope
Bus Send Angle 5, 13 Envelope Sets the color of this parameter’s automation envelope
Bus Send Angle 6, 14 Envelope Sets the color of this parameter’s automation envelope
Bus Send Angle 7, 15 Envelope Sets the color of this parameter’s automation envelope
Bus Send Angle 8, 16 Envelope Sets the color of this parameter’s automation envelope
Bus Send Focus1, 9 Envelope Sets the color of this parameter’s automation envelope
Bus Send Focus 2, 10 Envelope Sets the color of this parameter’s automation envelope
Bus Send Focus 3, 11 Envelope Sets the color of this parameter’s automation envelope
Bus Send Focus 4, 12 Envelope Sets the color of this parameter’s automation envelope
Bus Send Focus 5, 13 Envelope Sets the color of this parameter’s automation envelope
Bus Send Focus 6, 14 Envelope Sets the color of this parameter’s automation envelope
Bus Send Focus 7, 15 Envelope Sets the color of this parameter’s automation envelope
Bus Send Focus 8, 16 Envelope Sets the color of this parameter’s automation envelope
Bus Send LFE 1, 9 Envelope Sets the color of this parameter’s automation envelope
Bus Send LFE 2, 10 Envelope Sets the color of this parameter’s automation envelope
Bus Send LFE 3, 11 Envelope Sets the color of this parameter’s automation envelope
Bus Send LFE 4, 12 Envelope Sets the color of this parameter’s automation envelope
Bus Send LFE 5, 13 Envelope Sets the color of this parameter’s automation envelope
Bus Send LFE 6, 14 Envelope Sets the color of this parameter’s automation envelope
Bus Send LFE 7, 15 Envelope Sets the color of this parameter’s automation envelope
Bus Send LFE 8, 16 Envelope Sets the color of this parameter’s automation envelope
Bus Send Width 1, 9 Envelope Sets the color of this parameter’s automation envelope
Bus Send Width 2, 10 Envelope Sets the color of this parameter’s automation envelope
Bus Send Width 3, 11 Envelope Sets the color of this parameter’s automation envelope
Bus Send Width 4, 12 Envelope Sets the color of this parameter’s automation envelope
Bus Send Width 5, 13 Envelope Sets the color of this parameter’s automation envelope
Bus Send Width 6, 14 Envelope Sets the color of this parameter’s automation envelope
Bus Send Width 7, 15 Envelope Sets the color of this parameter’s automation envelope
Bus Send Width 8, 16 Envelope Sets the color of this parameter’s automation envelope
Bus Send Front/Rear Balance 1, 9 Envelope Sets the color of this parameter’s automation envelope
Bus Send Front/Rear Balance 2, 10 Envelope Sets the color of this parameter’s automation envelope
Bus Send Front/Rear Balance 3, 11 Envelope Sets the color of this parameter’s automation envelope
Bus Send Front/Rear Balance 4, 12 Envelope Sets the color of this parameter’s automation envelope
Bus Send Front/Rear Balance 5, 13 Envelope Sets the color of this parameter’s automation envelope
Bus Send Front/Rear Balance 6, 14 Envelope Sets the color of this parameter’s automation envelope
Bus Send Front/Rear Balance 7, 15 Envelope Sets the color of this parameter’s automation envelope
Bus Send Front/Rear Balance 8, 16 Envelope Sets the color of this parameter’s automation envelope
Event List Note Events Color of note events in the Event List view
Event List KeyAft Events Color of key aftertouch events in the Event List view
Event List Control Events Color of controller events in the Event List view
Event List Patch Events Color of patch events in the Event List view
Event List ChanAft Events Color of channel aftertouch events in the Event List view
Event List Wheel Events Color of pitch wheel events in the Event List view
Event List Sysx Events Color of System Exclusive events in the Event List view
Event List Special Events Color of other, special events in the Event List view
Note that is on Color of currently playing notes
Events Color of selected events in the Piano Roll view
Navigator Background Color of background in Navigator pane and view
Navigator Track Rectangle Color of the Navigator pane triangle that shows what the part of the Clips pane is currently displayed
PRV Drag Contents The color that a MIDI event becomes while you’re dragging the event
Snap to Scale Excluded Rows Color of pitch rows in Piano Roll view (or Inline PRV) that become unavailable when Snap to Scale is enabled.
Continuous Event 1 The color of the first type of continuous event entered into the Piano Roll or Inline Piano Roll view
Continuous Event 2 The color of the second type of continuous event entered into the Piano Roll or Inline Piano Roll view
Continuous Event 3 The color of the third type of continuous event entered into the Piano Roll or Inline Piano Roll view
Continuous Event 4 The color of the fourth type of continuous event entered into the Piano Roll or Inline Piano Roll view
Continuous Event 5 The color of the fifth type of continuous event entered into the Piano Roll or Inline Piano Roll view
Continuous Event 6 The color of the sixth type of continuous event entered into the Piano Roll or Inline Piano Roll view
Continuous Event 7 The color of the seventh type of continuous event entered into the Piano Roll or Inline Piano Roll view
Continuous Event 8 The color of the eighth type of continuous event entered into the Piano Roll or Inline Piano Roll view
VU Lo level Sets the color of the lower portion of a non-segmented meter.
VU Hi level Sets the color of the higher portion of a non-segmented meter.
VU Tick Marks Sets the color of the numbers and calibration lines of a non-segmented meter.
Console Segmented VU Tick Marks Color of tick marks in segmented meters in the Console view
Enable/Disable Toggles Sets the color of the enable/disable check box on effects and other objects that have an on/off switch
Console FX Bin Text Color of text in Console View’s FX bin
Console View Control Text and Values Color of text on Console View’s controls
Console View Slider Background Color of border area of Console view fields controlled by sliders
Console View Strip Background Color of empty space in Console view
Console Audio Track Name Text Color of text of audio track names in Console view
Console MIDI Track Name Text Color of text of MIDI track names in Console view
Console Synth Track Name Background Color of background of Synth track names in Console view
Console Synth Track Name Text Color of text of Synth track names in Console view
Console Instrument Track Name Text Color of text of Instrument track names in Console view
Console Bus Name Text Color of text of Bus names in Console view
Console Main Output Name Text Color of text of Main Output names in Console view
Console View Strip Label Text Color of meter peak values in the Console view
Console EQ Plot Grid Color of grid lines in per-channel EQ plot in Console view
Console EQ Plot Graph Color of EQ curve in Console view’s per-channel EQ plot
Synth Rack Text Color of text in the Synth Rack
Dialog Box Banner Text Color of the headings that separate different parts of a dialog box page
Dialog Box Banner Background Color of the background behind a dialog banner heading
Track View Header Time Display Color of time display above track strips in the Track view
Ghosted clip background Color of clips when editing automation envelopes.