For my bobbin thread, I use a thin filament polyester thread. It lasts so much longer per bobbin than the thicker cotton thread and I haven't had a single break since I started using it (on the bobbin side, anyway).
As for the top thread color, I try to buy white in bulk and use that, but if I run out I have no problem using colored thread. My only caveat would be if I'm sewing white muslin or another light-colored fabric. Then a dark thread color might show through the seam fold. Unlikely, but I have enough light-colored threads to just choose them.