A garish saffron skin offsets the gnashing and gnawing teeth of the frightening fiend's ilk. They summon lashings of lethal thunder with which to strike and threaten the whole party, and also unleash a dodgy dance that ups their Evasion and allows them to dive away from damage, while blinding, cursing, and sapping their enemies' Defence.
It is unknown why the hellstalker's color palette shifted from purple to tan brown in the transition from VI to VII. However, its former color palette is used for the demon thunderer that debuted in VII and has consistently used that color palette since then.