Question What do the colors of all the lightsabers mean?
Red
Blue
Yellow
Green
Purple
(White?)I've heard about it.
Answer Although lightsaber colours may have metaphorical representations, these representations are still quite ambiguous, as George Lucas or any other Lucasfilm personnel hasn't really talked about it much. Generally, in the Star Wars films, a red lightsaber is used to represent a Sith, and a blue and a green lightsaber are used to represent Jedi. Initially, Mace Windu was not supposed to acquire a purple lightsaber. However, Samuel L. Jackson, who evidently played Mace, asked George to give him a brand new lightsaber colour, simply to set him apart from other Jedi and to make him unique (Sam Jackson is a very big Star Wars fan). Sam's wish, as we can see in "Attack of the Clones", was granted.
As for the yellow lightsaber, this particular kind was never actually shown in the films. Rather, it was shown several times in video games (perhaps most recognizably the one used by Plo Koon). So when it comes to its significance, all I can say right now is that it was created for the sole purpose of creating another lightsaber colour. (But keep in mind that the films, not the video games, are Star Wars canon. Fortunately, since Jedi can have multiple lightsabers, it is difficult to make contradictions between lightsaber colours in films and lightsaber colours in the Expanded Universe.)
Finally, I have also actually heard of the white lightsaber before. As it turns out, this "white" lightsaber was merely an editing mistake in "A New Hope". If you watch the original version of "A New Hope", you would see that after Vader and Obi-Wan's battle, Vader's lightsaber can be seen as white in colour instead of red. This mistake has been corrected in the DVD version (I know some people may be very emotional over what I'm about to say, but the DVD versions of the original trilogy ARE the final versions. Some may not consider it as such, but that's how I personally consider them to be. Anyway, let's get back on topic.) Several fans also claim that Luke Skywalker's lightsaber in "A New Hope" seemed white, which is probably another catalyst to the "white" lightsaber urban legend. So, just to sum up this whole paragraph, there is no white lightsaber.
Thanks for the questions. Feel free to ask again if there are any ambiguities in my response.
