I think the little balls of Perle cotton that I use for red work embroidery would work. It comes in a vast array of colours and because it is one strand it is easier to work with. I use # 8 and it is about as thick as embroidery thread. You can also test your embroidery thread by putting a wad in hot water and then placing it on a white paper towel to dry. If it has any colour on the towel after drying, it is a bleeder.