I did a lot of spotting on my trip to the US in the first two weeks of July 2000, and have seen loads of Delta 727s, especially in Atlanta. Of the 49 DIFFERENT 727s I saw, 25 had the old-old livery, and 24 the old-new (1997-1999) colours! Because no 727s are reported yet in the new-new livery, this breakout must be still the same. I don't know, maybe Delta dedicates the 727s with the old or old-new colours on certain routes, but otherwise your chance to catch one in the old-new colours is almost 49% !
nobody has ever died from hard work, but why take the risk?