I agree with Prism99---just color the thread- i am assuming you have never (un-sewn) a quiled piece----it is quite a job! i had some tension problems one time on a quilt just over a 9" by width of quilt space---it took almost 7 hours to remove all of that quilting! i learned right then to ALWAYS check to make sure everything is going well top and bottom everytime i change a bobbin- or stop for any time- i check within a few inches...
but your (problem) is a much easier fix---it is easy to color the threads any color you choose.
