Dark Assasin - I think they're saying you wouldn't be able to see it well in the finished product of the movie. In ROTJ, Luke was supposed to have a blue saber since the hilt was based on Obi-wan's and everything, and even the promo art and original poster have him with a blue saber...but, when ILM tried to do the scenes over the sarlaac, the saber would seem to "disappear" when in front of blue sky. Now imagine the problems of a pure white saber, especially that bright. Besides, Lucas likes to use colors as character traits, red is anger which is a sith trait which factored into the idea of all sith using red. Why would Sidious, the friggin' Uber-Sith break tradition?