Tone Down Meaning

(idiomatic) To relax; to make quieter or less obtrusive; to make milder.

Example:   Ask them to tone down that orange and pink color scheme a bit.
  I hope they'll tone it down and stop arguing so much.
Charles Kingsley
  its thousand hues toned down harmoniously
To moderate or relax; to diminish or weaken the striking characteristics of; to soften.
  The best method for the purpose in hand was to employ someone of a character and position suited to get possession of their confidence, and then use it to tone down their religious strictures.
To make a television program, piece of writing, etc. less offensive and so more suitable for a family audience.