Realm of the Veil
The souls of the Cosmos, when lost in their way, are sent to Velamus. Or something. Going a bit meta with this because I am not sure how to write it pretty enough even for a draft. Basically, Velamus is where your soul goes when
Putrus is the Shadow and Light Realm, it is located in the Death's Hourglass Constellation.
All of Velamus is completely grayscale, even when non-native stuff arrives to the realm.
Endless night with a glowing moon. It is the only constant source of color in the realm and even then it is only a faded slate gray of light.
Caretakers, Soul-Seers, and a variety of other Sophonts that care for, repair, and deal with souls. All of them are not quite living and not quite dead. Many of them have eyes that glow and give off colors to that which their eyes light up.
Think of the classic spooky dead forests, cursed swamps, and haunted victorian landscapes. Now make it grayscale and with a little fog. All those plants? They exist.
Fish fly through the sky, guided by orbs of light they produce over their heads. This light can actually show color of the world. But watch out, they feed on lost souls. I have a bunch of art for this.
Souls are carefully purified and turned into Raw Glow to be returned to the Cosmos. Faith is drained, and so is Primal. All to be balanced out.
They are beyond our understanding of magic, basically.
Realm of Veil
Denizens of Ravare do not know of Velamus.