I buy cream/neutral and gray thread for all my piecing. I don't match piecing thread to the color fabric, I'd go nuts doing that. All the name brand threads are good quality. The higher the no. the thinner the thread. Try a spool of several brands to find the one you and your machine likes. I get great results from Essential thread from Connecting Threads on line. I use it for piecing and for some machine quilting. I have some of every brand and use them all. My very best favorite for machine quilting is Glide from FelTec and silk mini cones from YLI. Most thread websites have pre filled bobbins, you can't go wrong with buying a neutral color to try out a thread.