Tone

v. t.
  1. To utter with an affected tone.
  2. To give tone, or a particular tone, to; to tune. See Tune, v. t.
  3. (Photog.) To bring, as a print, to a certain required shade of color, as by chemical treatment.
    4. To tone down
    1. To cause to give lower tone or sound; to give a lower tone to.
    To tone up ,
    to cause to give a higher tone or sound; to give a higher tone to; to make more intense; to heighten; to strengthen.