I had trouble with the color scheme for the first panel. In that panel they are entering in the region called the Gloaming.
Pelkern is a subterranean world. Deep underneath the surface of Pelkern there is an unbelievably vast Ocean, filled with massive mountain ranges. The “Kerns” are the lands found honeycombed within the mountains–these are the places where people are able to breathe and walk and live. There is a wide diversity of biomes you can find on Pelkern, but you can break them down into four categories:
1) The Bright Lands. These are wild lands overflowing with life and light. Like the Amazon jungle found on Earth, these Biomes are dangerous lands to tread, and only fools enter unprepared.
2) The Gloaming. The Gloaming is the name for the large zones that border Bright Lands. These Biomes are less dangerous than the Bright Lands, and it is here that the People of Pelkern make their dwellings and live out their lives.
3) The Tenebris. The Tenebris is where the Gloaming peters out into utter darkness. Not much, if anything, grows in the Tenebris, so the air grows thin. Lands that have been devastated by fire or other disasters often turn to Tenebris.
4) The Deeps. This is the Ocean outside the Kerns, and the People of Pelkern cannot survive or access it, but they know of its existence.