Boneyards Below Chymins

Boneyards Below Chymins enters play tapped.
{t}: Add {1} to your mana pool.
As long as Boneyards Below Chymins remains in play, you may pay {g/w}, {r/g}, or {r/w} as if they were {1}.
To the caverns below the winding mazes of the spire Chymins, all people are drawn.