If you have played Diablo 2/3 you should be familiar with the colors already.
- White = Normal (can be upgraded to Magic or Rare and can reforge stats)
- Blue = Magic (can be upgraded to Rare)
- Yellow = Rare (can be upgraded to Rare and can reforge stats)
- Orange = Unique
- Gold = Orbs and Scrolls
- Dark Green = Active skill gems (can upgrade quality)
- Light Green = Quest items