I would call this natural or off white. New Hidamari Sashiko thread, 100% cotton on 30 meter spools. If you would like a thinner sashiko stitching thread for a lighter looking stitched line, this is a good choice. It is a firmer thread, so it doesn't have the slight fuzz of the softer 20 meter Olympus sashiko thread skeins, and it it truly a matter of preference whether this is a better feature :-)
Made by Cosmo Lecien, you can trust the quality of this thread for sashiko stitching, visible mending, and boro. Try it for embroidery and other hand stitching projects, and for big stitch quilting as well. It has the qualities we all want: it won't shrink, bleed or fade with washing, and it is easy to handle.
I suggest pairing it with lighter weight or tighter woven fabrics, and for needles I would choose the Hidamari Sashiko, Tulip Sashiko, or Clover short Sashiko needles.
There are 20 solid colors and 15 variegated colors available in this size"22/6 thread , as well as needles and ready to stitch pre-printed fabric kits. Look in Sashiko Supplies.