The colour purple to higlight the runs is chosen well I think
But the clolour of the strating node can be confusing, it is red and has the same form as a ‘not yet run node’. Maybe it would be an idea to change it to blue to distinguish it from the ‘not yet run nodes’
Mutatis mutandis for the green end node of a run.
An other, mayby better and or supplemental option could be to change the shape of the start and end node of a run/walk?