1 Oct 2007
The mana can be two mana of the same color, or one mana of each of two different colors. The mana can't be colorless.
1 Oct 2007
You can use this mana to pay an alternative cost (such as evoke) or additional cost incurred while casting an Elemental spell. It's not limited to just that spell's mana cost.
1 Oct 2007
The mana can't be spent to activate activated abilities of Elemental sources that aren't on the battlefield.