Text (IN+errata): Players can't cast spells that share a color with the spell most recently cast this turn. [Oracle 2009/07/08]
Does not affect the first spell played each turn. [Invasion FAQ 2000/10/03]
If a spell's color was changed while on the stack, use the color at the time it was when you started announcement, not as it currently is on the stack or as it was at the time it resolved. [D'Angelo 2000/10/14]
