Painted blood on the pedestal of a sculpture?

Last spring I wrote "A reminder that ancient statuary was often painted" (q.v. if you weren't reading the blog then).  I wonder if the painting above shows another example of this practice.

The piece is entitled Children Playing before a Hercules Group," by Adriaan van der Werff (1687).  A brief search didn't provide me with any discussion/analysis of the painting itself.  What I find interesting is the pedestal holding the sculpture of Hercules clubbing the ?monster.  It appears that red pigment/paint/blood is dripping down from the scene of the battle.  I wonder if that was done by the original sculptor, by the public as a form of graffiti, or whether I'm misinterpreting pollution/weathering etc.

Are there any art majors out there who can step in with some authoritative musings about this??

Image via Miss Folly.