The Corona and Chromosphere
When an eclipse of the Sun is total, the solar corona can be seen as a white halo around the black disk of the Moon. Except during a total eclipse, the sky is too bright for the faint corona to be visible, though it extends for many times the size of the Sun's yellow disk. The light of the corona comes partly from glowing atoms and partly from sunlight scattering off electrons and dust particles. The shape and size of the corona varies through the 11-year sunspot cycle. Eclipses are important for studying the solar corona.
The solar corona during the total Eclipse of 1980. Jay M. Pasachoff.
The chromosphere (sphere of colour) is the thin layer of red glowing gas around the Sun which is visible briefly at the start and end of totality. Pink is the colour hot hydrogen gas shines. Prominences are sometimes seen like pink flames. These are tongues of hot gas leaping up from the Sun's surface.