Regarding numbah's comment about a purple light saber I post this thought.

Now I gotta admit that light sabers look neat, but how in the world do they work? Light is such, that one beam would merely pass through the other. It would be like fighting with flash lights. Also light keeps on going and doesn't stop about a yard from the hilt of the saber.

Many experts conclude that some form of plasma that heated gases to a level where they emitted light would be necessary. Unfortunately, that would take a mechanism to keep the plasma in check as some type of magnetic force must be used. This means that the hilt would have to have an accelerator to whip up the gas, and some powerful generator to create the magnetic force. How could both these devices be fitted into the hilt?

A problem further arises in that a crafty opponent could carry a powerful magnet in his other hand, disrupt the magnetic force surrounding the plasma in your light saber, and the thousands of degrees of heat plasma would spill all over you. Bye, bye, Jedi!

There is another small problem with the plasma theory. The magnetic force field would shield the plasma and not allow it to cut anything. The light saber would be handy as a club, I suppose.

There is another theory dealing with quasars and quantum singularity that I don't understand enough to explain. Suffice it to say, that no known substance exists that is able to contain a quantum singularity.