Thought I would give an update even though it is an "even" day.
After taking a major chill pill last night, I re-evaluated my situation.
I could either unravel the whole project and start over, adjusting it so that the yarn I had would be sufficient. (So not going to happen...)
I could go to different stores and try to find more yarn and hope that the dye lots were close enough that it wouldn't matter.
I obviously went with the second.
Without divulging what the project is, since it is a commission for a GIFT...I can say that it has stripes. So, I am going to intersperse the new skeins with the old skeins until the old ones run out. The new skeins appear to be identical to the old ones, but better safe than sorry. Luckily they should be separated by enough space that any minute differences won't show.
(Postscript for my mother: I know I told you yesterday morning that I had purchased the rest of the yarn. But it turned out that it was the wrong brand. I hadn't taken the ball bands in with me at the store, and they had moved stuff around to mask how low their stock was. I grabbed yarn from the right aisle that was the right color, but the yarn I needed was wool/acrylic blend and the stuff I bought was 100% acrylic. I realized the error when I got to work. Called my friend, she told me they were out of what I needed. So...I got the right stuff at another store after work tonight, and will return the wrong stuff tomorrow.)