the.com/white lie

means A small, harmless untruth told to spare someone's feelings or smooth a social moment, rather than to deceive for gain.

from From 'white' used in its old sense of 'innocent' or 'favorable' — as in a white witch or a white flag — paired with 'lie.' The phrase has been around since at least the 1700s, when writers used it to describe fibs told out of kindness rather than malice, the color standing in contrast to the blackness of a genuinely harmful lie.