Did the Ancient Greeks Scour their Sculptures for Contests?

Here's a puzzle.  We have always heard that ancient Greek sculptures were painted and that the current look of such sculptures in museums is wrong since the painting is gone.  However, and I am not sure anyone else has ever mentioned this, Plato indicates that statues were scoured for competitions.  Wouldn't that mean to take off the paint?  Could it be that the Greek aesthetic ideal was without paint?  Here is the passage, where the scouring is used as an analogy:  "My dear Glaucon, how vigorously you have scoured each of the men in our competition, just as you would a pair of statues for an art competition."  Reeve translation, 361d. Admittedly, the scouring could just be a thorough cleansing.  The Shorey translation uses "polish" instead:  "how strenuously you polish off each of your two men for the competition for the prize as if it were a statue":  Shorey's translation does not imply that there were art competitions.  A polishing might just bring out the colors instead of scouring them off.