I ran into that problem today. I need enough black for one 2" by 8.5" strip. The only fabric store I have available only had one black and it's far from a match. I did purchase a small amount and will have to decide whether to use it or piece the little strip lengthwise. I had enough fabric, but cutting from a sitting position (wheelchair) I made several miscuts.
good luck with your unsewing - not a favorite.