Cherry Sue, no question is too silly for us - we all were new at this at one time or the other - as you see - most use the same color - if they are fearful that the bobbin thread will show - otherwise - usually the only time you would use the same color is in FSL. I have used the same color on a few monograms.
The only time I use the came color bobbin thread as top thread is for FSL. Carol
It seems to look better to me if I use the same color bobbin. By the way...your question is not silly. It helps others to learn as well.
If it can be seen I prefer to use the same colour. Otherwise - as on a shirt - I use bobbin thread.
No, but if your tension is not perfect you can see the bobbin thread on the front. You will see the back so, I try to use the color of the towel for the back or the color of the monogram.
I usually use the same colour in the bobbin if it's going to be seen, otherwise I use white (or black) bobbin thread.