I first started out using monofiliment so my FMQ mistakes wouldn't show and it was a good choice for me. I bet your skill has improved lots and colored thread would be fine to work with. I have sometimes used 2 or 3 colors, like a matching one on the boarders and sashings. It is a personal choice-Do you like the look of unmatched threads running across the blocks? It depends on the individual quilt to me. As for the thread popping I think it must be something with tension. I'm not a good one to advise on that. Be brave and try colored thread-bet you will surprise yourself!!