I've used different colored thread several times, with varied results, LOL! The trick is to get the tension as perfect as possible, so that - in a perfect world - the threads meet exactly inside the quilt sandwich rather than above or under it. Of course, this is not as easy as it sounds when it comes to real life :-)
If you are going to quilt only straight lines it shouldn't be too difficult, though. Try out the tension by sewing on a small scrap piece with the two different threads and the same fabrics and batting that you have used in the quilt. Just adjust it until you're happy and don't see either thread appearing on the other side.
If you are going to free motion, it is a bit more difficult. The tension keeps changing slightly as you change sewing directions, so you need to choose an average thread tension setting that you can live with. Since the "wrong" thread will no doubt show in some places (particularly in sharp curves), I tend to think that I prefer it to be on the back rather on the front. So, if you can't find a perfect tension setting, settle for one that occasionally shows a little bit of thread on the back, rather than on the front of the quilt. At least that's what I would do... :-)
I too would be interested in hearing other's experience of different thead colors!
This post has been edited.
5/19/2008 9:01:38 AM