3. (Photog.) To bring, as a print, to a certain required shade of
color, as by chemical treatment.
To tone down. (a) To cause to give lower tone or sound; to give a lower
tone to. (b) (Paint.) To modify, as color, by making it less brilliant
or less crude; to modify, as a composition of color, by making it more
harmonius.
Its thousand hues toned down harmoniusly.