Honestly, I've never been able to see a difference in dye lots, but apparently a lot of people can. There was a little blurb on this in the latest issue of
Crochet World & the suggestion was to, if at all possible, have the new dye lot separated from the old in some way, which of course is fairly easy to do if you have a two or more colored pattern. Failing that, I'd try to isolate the new dye lot on a separate element like the sleeves, or at the least make
very sure you start a new row/round with it, so you can better make believe that you meant to do that all along.
