For my light-sided Sith Inquisitor, it has nothing to do with good or evil. Rather, he's more of an honorable warrior type of character (as opposed to the greedy, betraying, power-hungry stereotype). He makes rational, reasonable choices that benefit the Empire or would benefit himself in the future (why kill someone and waste a potential resource when you could recruit them to your side?) To the Sith that challenge him, he has no issue with defeating them in battle, though he would usually prefer to spare them after proving his own strength. As for the Jedi and the Republic, they all die (with a few exceptions) as they are all threats to the Empire.
So yeah, Light V and not a traitor.