If you refer to an untrue statement as a white lie, you mean that it is made to avoid hurting someone's feelings or to avoid trouble, and not for an evil purpose.
white lie in British English
noun
a minor or unimportant lie, esp one uttered in the interests of tact or politeness
white lie in American English
a lie concerning a trivial matter, often one told to spare someone's feelings
Examples of 'white lie' in a sentence
white lie
And telling a white lie means you avoid the inevitable lecture.