I was making a Navajo design quilt...like a bargello, you have to have several different fabrics and move them up and down to get the color patterns of the quilt. Some how, I had left out one color in one of the strip set and without realizing it sewed the whole quilt together. I had a bunch of snipping and resewing to do on that one.
Now, I inspect my design often to make sure the colors are all there and going in the right directions.