When I started out in 1992 (has it been that long??) I used a stark white. It had a tendency to show on just about anything, light or dark. Now I prefer a soft grey, or deep cream. When I am making a scrappy quilt, it is just about impossible to match to everything.

Gray, taupe and tan are my go-tos for piecing multiple color blocks.

The best way is to audition various spools of thread by laying them down one at a time like stippling and see which thread matches the best.

I do this!!! I have greys and tans in a few different shades.

Hmm, I usually use bright red Aurifil (have about 30 spools of it) to piece unless I'm sewing white fabric. I have never been able to see the stitching thread in the seams from piecing. When I first started quilting, the quilt magazines then had long detailed articles and one article explained why red was a great neutral to use for piecing different color fabrics. And it's fun to have red thread on my machine. Makes others to HUH?

I just use off white for piecing everything. I always have several spools of it on hand. Once it's quilted and washed you can't really see the thread in the seams anyway.

Now quilting thread is a whole other story. I agonize over that for a while, then pick something I have on hand. I bought two twelve-packs of assorted aurifil thread earlier this year so I think I'm set.

I piece all my quilts with either dark tan, light tan, dark gray and light gray. I used to fuss over finding a thread to match my fabric and that was a real pain. Now I only use the above colors and have never had a problem. I am now piecing a black and white quilt and using the light gray. It's working great.

Try using a shorter stitch length. I normally piece with a 2.0 stitch length (and keep my fingers crossed that I don't have to rip out, but when I've had to, it isn't really that hard). I've found that using a shorter stitch length keeps the stitches from showing when the seams are spread open.

I use a beige or grey thread for most of my piecing.