Ditto :thumbup:

I use a cream or gray as they blend in well.

The thread is only in the seams if you do what is called 'stitch in the ditch'. If you do free motion quilting or hand quilting or sashiko quilting, the stitches appear all over the quilt in a decorative pattern. If you are talking about the piecing, when different colours are used against each other, you need to have a thread that blends in with both colours. It depends on the colours that I am using as to what I select. I use grey, maroon, brown mostly.

In garment consturction it is important to match the thread. If there is stress on the seams the color of the thread will show, and of course in hemming and topstitching it also shows.
From what I see in the responses, folks don't match thread when they piece. But for quilting, having matching thread can hide your stitches a bit better, and also change the character of the finished quilt.

I don't match my threads when piecing. I just pick a thread that is somewhat neutral and go for it. I do try to be careful when quilting as that thread will show. That was a good question and one that needed to be asked. Just use a neutral thread and go for it.

I belong to the neutral bunch. I usually use gray or a neutral cream color to piece with. Occasionally, if I am making just a two color quilt, I will try to match the thread, but that is seldom. Just do your own thing.

I only match when I applique. I use light grey for most piecing and dark grey or black if black.

Golly Ghee, I have been one to match colors when sewing, I suppose it is a carry over from sewing garments! What a welcome relief to know it really doesn't matter that much! Now appliqueing it does matter...

funny question..i usually use light colors and the bobbins i use up all the different (lights) ones that have a little bit on thread on them..i do alterations and always have tons of bobbins with threads i might have only needed a little of...THEN i have all empty bobbins !!

the only time i match thread is when i am doing the quilting