Ask a Warrior Thread.

But by charging, we get the carge afterimage, and not the red one from mastery.

Paladins "can" have red attacks, but only when they're charged and using their basic swings against a box or something.

Paladin's only have the charged swings when they are attacking mobs or nothing at all. When a Paladin attacks a box or some other object that can be broken, then the swing has an uncharged animation, which is red if he has at least Level 5 ACB and a charge active.