Something that has been ticking at my brain... There is a huge emphasis in game based on Color, especially Blue, Black, White, and Red.
Ragna and Nu-13 wield the false Azure Grimoire, yet Ragna is clad in Reds and Blacks; and Nu-13, likewise, is predominantly in Whites and Blues
Hazama/Terumi is the Black Susano-o and creator of the false Azure Grimoires.
Haku-Men is the White Susano-o
The NOL Creed, "Dispatched in mankind's darkest hour, we are Knights of the Blue Flame!"
The different branches of the NOL color motifs: "Shimmering Blue Flame," "Corrosive Pitch Black," "Incorruptible Pure White"
Bolverk exploding into Blue and Red energy before Noel was consumed by Blackness and shoved into Adventus to be tempered into Kusanagi.
Just about ANYTHING meaningful Arakune says involves color of some sort.
Not to mention the bright, vibrant colors that dominate each character's appearance. Each of the major characters (Ragna, Terumi, Jin/Haku, Saya, the Murakumos (Lambda, Noel, and Nu), Litchi, Arakune, and Rachel) have at least one or more of the four colors as a dominant part of their design.
Just a nagging thought in my head I got from a translated line in the CS console theme "Until the world is covered in Azure."
