Paladin - Smite Fire to Lightning conversion...

[doooooorgassssss]

So I really like this skill, but the Paladin has only Physical and Fire damage bonuses on his skill tree, so wouldn't this gimp my Smite's damage, due to the damage conversion?

Because it looks weird that the Paladin has a Lightning themed skill, but has no passive bonuses dedicated to Lightning damage and I feel all the other Fire bonuses are going to waste on this skill...