Blavatsky
Original sense
The aura is the radiation of the human constitution — a magnetic, vital, and psychic atmosphere. Sensitive people and adepts can perceive it; it is affected by health, thought, and passion. She did not publish the later rainbow chart of bands and chakra colors.
The aura is the emanation from the inner man, a magnetic atmosphere that surrounds every living being.
Leadbeater’s Man Visible and Invisible (1902) painted the egg of colored layers that New Age posters still copy. Blavatsky supplied the premise (an emanation that reveals inner states) without the standardized palette.