Call the doctor! The patient still looks a bit green about the gills! At Matthew Marks Gallery last week, a panel of experts rated the current health of the art market. “I give it a six,“ said Chelsea art dealer James Cohan, in so many words, with art advisor Michele C. Quinn putting it at ca. 65 percent. Todd Levin of the Levin Art Group was the more pessimistic, giving it a “five.“.