Luke's saber is consistently blue in the original Star Wars. And no, I have no plans to restore the other two films, "The Soap Opera" and "The Muppet Show." :) Best leave those to somebody who cares as much about them as I do Star Wars.
By the way, a note about how dark the Blu-Ray is: film contains an awful lot of information; a lot of density and latitude in the image. When scanning, you never want to lose information in the darks or in the highlights, so you make sure to preserve the full range of information (or as far as is possible on the scanner - most film scanners capture a very limited range of film density compared to the best drum scanners, for example). In any case, what happened was that they took data which was properly scanned, and made sure to preserve the top end highlights and deepest blacks, but it's the distribution of all the mid-tones that's wrong. Why? I dunno; didn't look at any reference images? There's no "absolute" setting when dealing with either linear or logarithmically scanned images, though Cineon specifications are fairly consistent. Nonethless, the data is in there, it just wasn't handled properly. That said, what ISN'T in there is the color fidelity. That limited color palette was not a choice; it's in 1997 prints. Or should I say, the range is already limited in 1997 prints.
_Mike