If all you can find is the color but not the dye lot, you can work with that. It may require ripping out the last several rows that you knit but you can work 2 rows in the old yarn and 2 in the new and continue to alternate. Eventually you'll shift to all rows in the new dye lot. It makes it very difficult to tell where the yarns shift dye lots and in a pinch, it works.
There are several on line outlets that have the color, but none of them list the dye lot. Might be worth inquiring through their contact forms though. WEBS, Alpaca Direct, Loopy Ewe, and Jimmy Beans all listed the color as "In Stock".