Although the color may be altered, any restrictions on the use of the mana are not removed.
Will not affect lands that do not produce mana.
This has the supertype world. When a world permanent enters the battlefield, any world permanents that were already on the battlefield are put into their owners' graveyards. This is a state-based action called the "world rule." The new world permanent stays on the battlefield. If two world permanents enter the battlefield at the same time, they're both put into their owners' graveyards.
Colorless mana added to a player's mana pool isn't affected.