There are some others colors that blend in really well. I don't have a spool with me right now, but it is kind of a cinnamon color. That one works well for many piecing colors. I like the light and darker grey too. I find I don't use much of the really light colors. I tend to piece more medium colors than really light, so I use more of those colors.
Have fun shopping. With the thread being thinner, it goes a long way. It's really good for the actual quilting too.