What do the different color auras do?

Solution 1:

There are five auras:

  • Green: Healing Aura
  • Orange: Flame Aura (fire-based periodic damage)
  • Purple: Drain Focus aura
  • Red: Speed aura
  • White: Toughness aura (increases enemy's armor)

Note these colors roughly apply to your characters' abilities too. For example, the badges for Anjali's fire talents and abilities are orange-tinted, and many of the healing abilities are green-tinted. I guess you can consider it to be Dungeon Siege III's version of an elemental system.