I don't really see the point of special attack or defense dice. You can accomplish virtually the same effect by simply adding or subtracting attack/defense dice.
I'm not opposed to more dice though. I would just want them to represent some new effect that is currently not in the game that requires a random effect.
There's a certain granularity to be gained when you change the kind of dice. Having only three real amounts of red dice to use for most applications means you don't have a lot of leeway.