And the answer is: it depends. The confusion comes from different leagues and different parks having different "yellow line" rules.
As far as I can tell, in ohio softball, you have to clear the fence no matter where a yellow line is, UNLESS there is a specific ground rule. But even then there is some debate.
It is. But the protective tubing on the fences along the foul/baselines are black.Pretty sure that is not yellow line marking a homerun. its the protective tubing to keep anyone from getting hurt on the top of a chain link fence.