Class P Star

A Class P Star is a spectral class of star that is massive enough to emit light on the Indigo and Violet end of the Light Spectrum. These are the most massive and the rarest spectral type in the universe. More specifically a type of Primordial or Population III Star. Although some instances of these stars still persist to this day.

Color
These stars are so massive and bright that they emit light on the Indigo and Violet end of the visible light spectrum. Basically these are giant purple colored stars. While Brown Dwarfs or Low Mass Red Dwarfs appear Megenta, these supermassive stars appear Purple in hue. Often more than not their emitted light would be seen as Indigo while their true color is Violet. This is because violet is the shortest wavelength, the further the light travels the more it redshifts so we would see such light from said star as Indigo if extremely far away.

Mass
These are stars that exceed the masses of the brightest O type stars reaching as much as 300 or more solar masses. As a result these stars tend to be metal poor or even metal absent. These stars were more common in the early universe shortly after the big bang.

Giant Stage
These stars are so massive that when they reach their giant stage the core collapses into either a neutron star or black hole in the process but instead of a supernova explosion it creates what is referred to as a Quasi-Star or a Thorne–Żytkow Object in the form of a TZO Hypergiant. in the case of the latter it will eventually go Hypernova as the mass surrounding the neutron star is consumed and a black hole forms blowing off the remaining layers.

Antimatter Production
Because of the mass of such stars it is possible for them to end up producing antimatter in their cores leading to the creation of so called Zombie Stars. Stars that undergo various supernovae but refuse to die out completely.

Trivia

 * This is based off of a hypothesis regarding Population III Stars and supermassive main sequence stars with metal deficiency.