Where can I buy on line, or get directions on line to make, garment dress clips?

I need to make, or buy, some of those clips. They are used to attach to your clothing, if you need to tighten it up some or gather some loose material. I don't want the ones that are made like broaches, but the kind that have elastic in the middle, and metal clips on each end. Kind of like the clips used on suspenders. I found some plain white ones, but I need some that are more colorful. I am losing weight and I do not want to buy any new dresses right away, and I thought they would be a nice way to make my dress look less sloppy, between sizes.