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.
All nonland cards you own that are not in play are white. All nonland permanents you control are white. All lands you control are plains. All colored mana symbols in all costs on all of these cards and permanents are oW.
--This card has no flavor text --