"Barbarian raids were a concern to those living in the northwest provinces, but the skyknights never dealt with the problem in a systematic way. They thought of the Balduvians as an 'amusing model' of their forebears' culture."
—Kjeldor: Ice Civilization
Lands you control are Plains.
Nonland permanents you control are white. The same is true for spells you control and nonland cards you own that aren't on the battlefield.
You may spend white mana as though it were mana of any color. You may spend other mana only as though it were colorless mana.