use whatever you want. i have used some of the serger cones when i don't have what i want. it still looks good. and i rarely follow the colors listed. i just find something close. alot of times i've found mistakes in the color lists. i was doing some tinkerbells and the color list wound up giving her red hair and black eyes. if its something like a shirt that can't be changed, then i test stitch if it's a new pattern. can't go wrong that way.