Just for amusement, you can try (separately, dismiss dialogs between commands):
Code:
$ am broadcast -a com.onyx.action.show.contrast.dialog
$ am broadcast -a onyx.action.SHOW_DISPLAY_CONTROL_AND_INCREASE_CONTRAST_ACTION
$ am broadcast -a onyx.action.OPEN_BRIGHTNESS
The first two bring up dialogs for me, the third doesn't