The folks at Dungeons&Dragons Online have posted part four of dev journal which looks at the artistic vision behind Shavarath, the Plane of Battle.
Unorganized and savage, each demon lives and dies on its own cunning and power. Yet when their bloodlust rises they congregate to form the fearsome Demon Horde. Bitter enemies of the devils and archons, they amass themselves for clashes with their neighboring rivals.
The demons, being Chaotic Evil, ruthless, and pitiless, were a challenge to bring to life in art that represented them. We decided that red and orange hues would be best, as the warmer colors would better reflect their violence and unbridled passions, unlike the calculating and organized devil legions.
Demons aren’t well-organized or structured, and therefore they are not good at constructing anything from their own materials. As evident by all things of their making, they tend to use debris or pieces from other cultures, and strap or bind them together for whatever function they need. A demon throne could be constructed from devil bones, or a demon shield from pieces of leather and lava-welded metals. Skulls and bodies of all races adorn their earthen lairs.
Read more here.