I run high vis on a number of my rods, several different colors and styles. I run it for different reasons. When I pull plugs, I use high vis so that while rowing I can keep track of where the plugs are, and what they are doing with out having to strain and pick them out of the back ground. I dont run the high vis straight to the plugs though, I tie about a 5 foot preleader of mono joined with a double uni knot.
When I bobber fish, I also run high vis, to help my eyes keep track of my gear. And in turn, having extra line laying around, more of my rods have the high vis on it. It doesn't have an effect on the fish. And in low clear situations, I tie a preleader where needed.