Primordial

Progenitors「原初の悪魔, Gensho no Akuma」also known as Primordials or Progenitor Demons, are the oldest and extraordinarily powerful demons. According to Leon Cromwell, each of them is referred to by their signature colors, in place of an actual name.

However, each one appears to have a name, or something similar:
 * Purple Progenitor (Violet) Ultima
 * White Progenitor (Blanc) Testarossa
 * Yellow Progenitor (Jaune) Carrera
 * Black Progenitor (Noir) Diablo
 * Green Progenitor (Veit) Mizari
 * Blue Progenitor (Bleu) Rhein (Hirari in WN)
 * Red Progenitor (Rouge) Guy Crimson

Appearance
Black: Wears a full butler attire with white gloves. He has black hair with a strand of red in the front.

White: Has silver hair, snow white skin, and red eyes. She is very beautiful.

Red: Has crimson red hair and is very beautiful.

Personality
According to Leon Cromwell, they are heretical and often troublesome because they fight using Technique and wits instead of Raw and Sheer Power like usual Demons. They continue to jockey for power in all its forms in the hopes of becoming the Prime Demon.

Chronology
The term first appeared in Extra: Black and a Mask, although the term Primordial was used in the side novel story The Lake Shore Dyed Scarlet Incident.

Guy Crimson's color was Red/Rouge. He was summoned as a demon by a weak-willed human to destroy an opposing country. He carried out the summons contract but also chose to destroy the country of the one who summoned him. He summoned two demons to rampage and destroy the country who were also members of the Progenitors, Green/Mizari and Blue/Hirari. Due to the numbers killed, he satisfied the requirements to become a True Demon Lord. He eventually became aware of the strongest being there was by the name of Veldanava. He challenged him and lost handily. Veldanava took a liking to him and gave him a purpose, to challenge mankind.

Black was summoned by a woman one of two members of Silver Wings, who begged him to do something to 'them'. "If you grant my wish, I don't care if you're a demon! You can have my soul! So, please... Make them... Make them..." Black agreed to her wish, and in exchange, devoured her emotions. Black then hunted down an Archdemon, supposedly fulfilling his contract.

Testarossa's color was White/Blanc. She was the demon of note in The Lake Shore Dyed Scarlet Incident. She possessed a young woman by the name of Blanche whom she befriended. Her kingdom had a pact with the demon to one day sacrifice the princess' body to the demon as a physical body as long as she kept them safe from other warring nations. This pact was cemented by the crimson eyes of everyone woman birth to the royal family.

Abilities
at first the strength of Progenitor were similar with Archdemon since they no longer could Evolve and Increase their Magic Amount which led them to Develop their own respective Technique and Skill which led the difference power between Normal, Named Archdemon and Progenitor in term of fighting skill despite having the same amount of Magic and being categorized as Archdemon.

Black's Abilities:

 Fire: The ability to summon fire

Claws: Black can produce very long, sharp claws on either hand

Speed:  Black is extremely fast, even to the point where it seems he is teleporting

Trivia

 * The Nickname of each Progenitor were from the French language of their respective Color.


 * There's no such thing as Progenitor in Web Novel due to Diablo's Hair color is Red and Testarossa's Hair color is Scarlet which completely contradicting with the Colored Demon in Light Novel. it's presumably though that the Demon in the Web Novel were only Red like Demonic being in Mythology.