I see how they can be used on approach shots to gauge how the green breaks in general.
However, when putting, do the dots not tell you all you need to know? I have never really paid attention to the coloured lines when putting as the speed of the dots can tell you the break and elevation etc.
Were the dots added as a feature after the lines?
If there is a good use for the coloured lines when putting I would appreciate anyone letting me know thanks, maybe I am missing something.