Samuel L. Jackson personally requested a purple lightsaber in Star Wars Episode II: Attack of the Clones.

Samuel L. Jackson personally requested a purple lightsaber in Star Wars Episode II: Attack of the Clones.

Throughout the six Star Wars films, lightsabers come in three colors: red, green, and blue....save for one extra-special Jedi master. While filming the Battle of Geonosis in Attack of the Clones, Sam Jackson asked George Lucas if his weapon could be purple to make Mace Windu stand out. Purple is Jackson’s favorite color and it is often featured on his movie characters. Mitch Hennessy wore a ring with a purple gem in The Long Kiss Goodnight, Mr. Glass wore purple clothing in Unbreakable; Jackson chose to have Doyle Gipson wear a purple hat in Changing Lanes; and Lazarus, his character in Black Snake Moan, plays a purple Gibson guitar.

Jackson also knew that Windu was to die in Revenge of the Sith, so he reportedly told Lucas that he would only do the film if he went out in a blaze of glory and not “like some sucka.”
Sources: (1, 2)