[phinds]

This is unquestionably a case of light (and possibly some grease) darkening the surrounding wood and as Joe said, you'll never get a perfect match. One possible solution would be to remount the base of the track lighting system but without the lights. Then you have a piece of metal strip on the ceiling that may be MORE obnoxious to you than the undarkened strip or it may be more acceptable. You are never going to get a really good match without a lot of sanding of the whole ceiling and that's quite a job, especially since it's not entirely flat (sanding those grooves makes it an even worse job).