I can't speak to color issues - never ran a roll of color through the LX when making long exposures (and rarely did so when making normal exposures). However, the Tri-X / LX combination produced very good exposures in automatic mode in low light, with no thought to, or adjustment because of, reciprocity failure.
Shel "You meet the nicest people with a Pentax" > [Original Message] > From: Rob Studdert > I believe that the LX is one of the best ever low light cameras, the pity is of > course that it doesn't have a pixel array. The LX seems to get the exposure > pretty much in the ball park during long exposures as other have indicated. > > Reciprocity failure can be a pain to manage and should be more so if you are > using auto exposure with off the film metering as in the LX. The subject > colour, the scene illuminants and the surface colour of the film all effect > exposure times, however after much testing over many years I simply learned to > trust the camera and bracket when it all looked too hard, I made a lot of great > exposures that way. :-)