tone something down
phrasal verb with tone verb [ T ] uk/təʊn/ us/toʊn/ (also tone up)
使（通常指文章或讲话）缓和；使温和
to make something less forceful or offensive, usually a piece of writing or a speech
Some of the language in the original play has been toned down for the television version. 这部戏被拍成电视后，原剧中的一些语言已经被改得不那么激烈了。