I use black material in some of my quilts so I do use up those odd pieces of thread. I only keep the basic colors, probably not more than 6 different colors right now. Before learning to quilt, I matched my thread to each project. Now I use gray and beige for most of my piecing and it works great. A friend who quilts all the time was given about 30 spools of dark eggplant thread and she swears it works on everything.