So I was watching Episode 4 on DVD, when I was watching the part where Luke is using the remote for training. Now...obviously I've seen this many times before, but never on an HDTV Monitor before (the movie wasn't in HD of course). I was watching this part, and for some reason, Luke's lightsaber has a greenish-blue tint to it instead of a off-blue color. Has anyone else noticed this, and why wasn't it changed when Lucas was doing the updating of the films for the DVD?

MTFBWY!