The answer, as far as I know is that you didn't find anything because there isn't. I have raised this issue with a person in Adobe several years ago - that time in respect of the gradient tool, which presents the same usability problem - it is often difficult to detect the pin from previous uses of the tool, which wastes time searching for it when trying to go back in for an edit. One would have thought it rather easy to introduce such a refinement (a selectable colour for the pins), but it obviously doesn't rate high enough yet on the Adobe priority list of application improvements. One way of overcoming the inconvenience is to stare intently at the image while you toggle the tool on and off several times, looking for this little button to appear somewhere around where you think you may have set it. A correctable nuisance.