This just happened to me so I thought I would share what I did. I matched the thread to the fabric so well for this project that it caused me a little problem. I had to rip out the point of a dart and resew it to avoid those pointy boob problems (you know what I mean). The thread matched so well that I found it hard to see the thread line to continue sewing from there. My solution was to take a bit of chalk and just go over the thread. This made it easy to see the thread line on that dark green fabric.