But you don't want black-blue crystal. Black sabers are one of things that distinguish lame players with no respect to Star Wars from everyone else.
Besides that - even ascetic wise they are no more than glowing sticks. It's like running with training saber while everyone around have real lightsabers.
I'm making a Sith Pureblood Jedi Sentinel with 1 red lightsaber and 1 blue lightsaber in 1.2. You mad?