The concept of "Indigo Children" originated in the 1970s through Nancy Ann Tappe's work on human aura colors and was later popularized in the 1990s.

Nancy Ann Tappe, a parapsychologist and synesthete, is credited with first identifying a generation of children with a distinct "indigo" aura color during the 1970s. She detailed her observations in her 1982 book, 'Understanding Your Life Through Color'. Tappe claimed to perceive life fields and described Indigo as one of 10-14 life colors that individuals could exhibit. The concept gained significant public traction and was widely disseminated through the 1999 book 'The Indigo Children: The New Kids Have Arrived' by motivational speakers Lee Carroll and Jan Tober. Carroll, claiming to 'channel' an entity named Kryon, and Tober presented a comprehensive profile of these children, asserting their unique psychological, spiritual, and sometimes paranormal traits.