A tip for buying extra shades is to buy 1 cone and wind off onto 2 or 3 machine bobbins if you want a match for a particular garment. Also have a light grey and a dark grey and maybe an off white or cream. You can mix shades as well say a darker for the upper looper thread, that is normally on top side, (think of a turned up hem on a skirt or trouser) and one that isn't quite such a good match for the under looper.