Immortal 18/Vengeance 23 or Imm 18/Veng 21/Rage 2 makes sense. Immortal/Rage would be an interesting - but highly situational - burst build as well. But Vengeance/Rage...? Honestly, impale will be on a 9-sec cooldown anyway so where would you put obliterate in the rotation? You'll already be juggling scream,smash, impale as the heavy hitters with ravage as a nice filler if you can lock someone down for just a few seconds. I can't be real sure, but I think you'll end up with more points wasted on veng/rage than with imm/veng. That, and with the 18 imm/21 or 23 veng you'd get a LOT more survivability. Free smash and subsidized force scream should mean you'll always have the rage to kick off an impale. Honestly, I think if you're going heavily into rage at all, go all the way. The 4 times per minute roflsmash is hard to beat that way.

The canon answer is that lightsaber crystals occurring naturally tend to produce green or blue colours. more rarely, yellow. The sith, having been run out of every civilized system for long periods, could not go close to many of the planets where natural lightsaber crystals were to be found, there usually being at least one jedi temple or outpost parked literally on top of the sacred cave/ravine/whatever. And so they started using synthetic crystals instead. With the method employed the natural color produced by a synthetic crystal will always be red. Using sith alchemy (or, from the jedi side of things, force infusion), the colour of the crystal can be changed. Most sith choose to use the traditional crystal, either out of pride or because the sith religion merely views the saber as one tool of destruction among many. Given how well the masters keep advanced techniques from their apprentices it's also not unlikely that the young sith constructing his own saber simply doesn't know how to alter the hue of the crystal, going from rote text. Sith alchemy is generally not a safe area to experiment in as a newbie. And this is why Jedi, looking for naturally occurring crystals, tend to have a variety of colours with blue and green being most common - whereas sith as a rule carry red blades. The idea that the lightsaber defines the jedi is also fundamentally flawed. A few thousand years before the swtor era sith carried war blades fashioned with the help of sith alchemy and jedi used similar weaponry. Even in latter eras some jedi renounced their lightsabers and settled for simpler weapons at times, such as staffs. Using ad hoc force infusion even simple sticks of wood could deflect lightsabers and crack rock. Sith war swords forged using sith alchemy had no need for such infusion but became, for all intents and purposes, indestructible, allowing deflection of lightsabers and blaster bolts, albeit requiring great strength to wield in comparison. Edit: You might make a case for synthetically created red crystal forged by sith alchemy to be unpalatable to a jedi - it might carry a "tinge" of rage or hatred from it's tempering - but I don't see this as forced. Jedi and sith have been stealing each other's lightsabers in combat in many books and quite a few movies and as someone had it above, Anakin had no trouble at all employing Dookus lightsaber. In fact, if this were true Jedi would have no difficulty at all sniffing out dark siders and hidden sith "Here, Chancellor, please just hold this and press that button....Nothing happened, eh? If you will accompany us, please, we have some questions for you...". And the reverse would be true. Hand every acolyte on Korriban a red saber and feed the guys who fail to use theirs to the nearest sithspawn. On the whole, enforcing saber use on light/dark is silly. Even grievous was able to swing four sabers at once, and he wasn't even force-sensitive. Of course you can see why Bioware did this - it wouldn't be properly star warsy if jedi ran around with red sabres and sith used green. In that respect it's backfired though. Line up any three sith warriors on a field and two of them will be toting blue or green due to them trying hard to get into Vette's knickers. Honestly, the idea of the anti-paladin carrying his own brand of honor around isn't per se bad, and the story line/conversation options kick ***...but it's too weighted. You end up with far too many players going down that road. On Korriban or dromund kaas I'd on the whole expect hordes of sith warriors to roam around the countryside righting wrongs, freeing slaves, rescuing kittens...an evildoer would be safer hiding out in the jedi temple than he would walking into the national capital. Haven't seen a sith inquisitor with a green saber yet though. I guess those 120+ affection hits you take from Khem Val with every light side option might be responsible for that. On the republic side though, i see very very few knights or consulars toting red around. Which makes sense. I would argue that a quest similar to the Jaesa quest line in order to determine whether Vette would be good or no would do wonders for that ratio. As is it's just too damn rewarding to go for light V as soon as possible.