I used to change if it was really dark fabric, but now I go with a deep cream, or soft grey and just leave it at that.

I try to use all of my half full or less bobbins to piece with just so I can free up my bobbins. I jut put them on the thread spool pin.

I also like grey or beige but at times just use my bobbins that have appropriate thread colors for the top thread. This is a good way to use up odd pieces of bobbin thread and give you a clean bobbin. I was buying 10 bobbins at a time but now all I do is empty the bobbins by using them to piece all kinds of odds and ends. I do a lot of stitch in the ditch before I even do the quilting so that keeps my quilts from pulling apart. I work on a domestic machine this might not work for a long arm.

I use neutrals such as different shades of grays, beiges and creams for piecing. If it is not a problem with the project, it is fun to use up bobbins, both on top and bottom, too.

I also use grey, beige, or white depending on fabric colors.

I use mostly beige, white or gray. I usually buy cones to use because they are economical to use. I like to piece with 50/3 thread. However, I do like to use the thread on bobbins just to free them up. I do not understand the concept of a bobbin with thread attached to the spool from which it came. I have about a dozen bobbins and that is quite sufficient. I also like to finish up a spool of thread that does not have enough thread for another project.

I agree with joe'smom, I use beige and grey with just about all my quilting except of course where the top is mostly white and then I do use the white thread. Seems to work out good.

When I have a little thread on a spool, I use that thread to get rid of it to piece.

I inherited a bunch of thread from my mother who no longer sews so I'm going thru them using the lightest colors 1st for piecing. Right now I'm working thru 8 spools of a medium grey thread. If I'm working on a quilt that is all light fabrics I will change over to a white, cream or beige thread just for safety sake. Otherwise I haven't notice the threads showing thru onto the front side.

Light beige 90% of the time. Medium gray for really dark fabrics. I have a cone of SoFine thread of each.