1
general::
Phrase(s): lend color to something
Fig. to provide an interesting accompaniment for something. • Your clever comments lent a great deal of color to the slide show of your vacation. • The excellent master of ceremonies will lend color to an otherwise dry panel discussion.
McGrawhill's American Idioms And Phrasal Verbs
2
general::
Embellish, especially to give the appearance of truth. For example, I'm sure he lied about reaching the summit; that detailed account about losing his pack merely lent color to the story. This expression uses color in the sense of "appearance of authenticity." [Late 1700s]
American Heritage Idioms