Answer Hi! I have those boots. I just went to look at them and the sole is either black or a very dark brown. It blends in well with the boot. I love these boots and have had many compliments on them. In fact a friend who saw me wearing them ordered them right away because she thought they looked great. I did order a half size larger. I usually wear merino wool socks and found the fit more comfortable with the half size larger. The calf of the boot fits me well, but my calves measure about 13 inches. Anyway, these boots have been great. I hope that answers your question.
Answer Yes, it's black; but since the entire boot is a dark color, it's very difficult to see much difference with the sole.