I use all hues of colors - depending on my mood. When I am strip piecing darks together, I like to use thread color as close as I can to the fabric color. I use white on whites, and then all hues of creams and greys. Right now, I am trying to use up as much small quantities on a spool as I can. The thread police may get me, but I use all thread, cotton, polyester, cotton wrapped polyester, polyester wrapped cotton - all together, as long as my machine can use it, it gets used. But new thread that I purchase, I am trying aurifil.