Spectral Amplifier

When Spectral Amplifier enters the battlefield,
if you only spent one color of mana to cast it,
it becomes that color. Otherwise, sacrifice it,
then draw a card.
Whenever you cast a multicolored spell, if
this is white, you gain 2 life. If this is blue, you
draw a card. If this is black, target opponent loses
2 life. If this is red, it deals 2 damage to target
creature. If this is green, you create a 2/2 green
Elemental creature token.