Dark lines below toe-rail openings

[SofiaB]

Perhaps I'm just too picky but the dark lines below the openings in the toe rails drives me crazy.  I've been debating adding rub strakes at gaps to allow heavy water to flow over, but light rain water to keep moving downhill, aft.  Possibly a bead of silicone?  It wouldn't take much to cause the water to run aft.  Or, block every other gap so less dirt lines. Has anyone done anything like this?  Thanks!  Stuart