Circle of Warding

If you control a Wizard, Circle of Warding costs {b}{w} less to cast.
If you control a Shaman, Circle of Warding costs {w}{u} less to cast.
If you control a Cleric, Circle of Warding costs {u}{b} less to cast.
If you or a creature you control would take damage from a Colorless source, reduce that damage by 2.