Personally, I liked the lighting in SW. I've read stories about how GL would go around, moving lights around, and Gil Taylor (the cinematographer) would get pissed and say to George that if there was a lighting effect he wanted, he should tell him and HE would do it, because as cinematographer, that was his job. I believe he won an Academy Award for his efforts.
The '04 DVDs do have a lot more contrast and saturation, but I don't think that has much effect on the original lighting.