1.
If you tone down something that you have written or said, you make it less forceful, severe, or offensive.
The fiery right-wing leader toned down his militant statements after the meeting...
We have had to ask the agency and their client to tone their ads down.
PHRASAL VERB : V P n (not pron) , V n P
2.
If you tone down a colour or a flavour, you make it less bright or strong.
When Ken Hom wrote his first book for the BBC he was asked to tone down the spices and garlic in his recipes.
PHRASAL VERB : V P n (not pron) , also V n P