10/1/2008: The only difference between a colored artifact and a colorless artifact is, obviously, its color. Unlike most artifacts, a colored artifact requires colored mana to cast. Also unlike most artifacts, a colored artifact has a color in all zones. It will interact with cards that care about color. Other than that, a colored artifact behaves just like any other artifact. It will interact as normal with any card that cares about artifacts, such as Shatter or Arcbound Ravager.
10/1/2008: Casting Salvage Titan by paying its alternative cost doesn't change when you can cast it. You can cast it only at the normal time you could cast a creature spell.
10/1/2008: You may activate the second ability only if Salvage Titan is in your graveyard. To pay this ability's cost, you may exile any three artifact cards in your graveyard -- including Salvage Titan itself. If you exile it to pay the cost, however, it won't be returned to your hand when the ability resolves.
Shards of Alara
(Rare)