Technically, Novak says the REd Wire stators uses a slightly larger gauge of wire, which means less resistance; less resistance means more power.
Perhaps they made a special exception for the 25.5 and it uses red wire of the same identical diameter as the old stuff, which would mean there is no functional difference.
If Novak could chime in (or if someone could measure the phase to phase resistance of a non-red 25.5 stator vs. a red 25.5 stator) we would know.