I just discovered how to do it! In BaseCamp when you double click on the trail name listed on the left side of the screen it brings up the track properties screen. In that screen on the upper right side there is a small box that you can click on to change the color of the trail. I was using that screen to check that the tracks were going in the right direction. I guess I was just concentrating on doing that and did not notice that color box there. So I am happy now!!